The interiors of cars are often subject to as much abuse as the exterior surfaces, yet are often neglected when it comes to detailing. It wasn't long ago that the state of the nation's car interiors made the news; apparently a very high percentage harbour levels of dirt and bacteria that are potentially unsafe to human health! If you stop and think about this it is not really that surprising. Most car interiors are only cleaned once or twice a year and the rest of the time dirt and grime is continually dragged in off the street, sticky messes are deposited by children (we know all about this one), bacteria are brought in by pets and all manner of other biological nasties are deposited by way of sweating, coughing, sneezing, vomiting or worse. In addition to the dirt and bacteria deposited by the occupants, the interiors of cars are subject to degradation by exposure to the more harmful rays of the sun, and the effects of regular variations in temperature and moisture content. Over time, porous surfaces such as vinyl and rubber tend to dry out, becoming increasingly brittle and in danger of cracking and splitting. The UV rays from the sun further degrade plastic and vinyl surfaces, resulting in fading and further surface damage. Large variations in moisture content, particularly during the winter months, can encourage the formation of mould and mildew, which can give rise to unpleasant musty odours.

In contrast to other detailing tasks, cleaning and protecting the interior of your is not as straightforward as you might think. If you own a relatively new car or have looked after the interior of your car relatively well then the chances are the advice given in this guide will be sufficient to enable you to achieve great results. However, if your interior has one or more of the following problems, you would be better off in the first instance employing the services of a professional valeter; badly stained fabrics and/or carpets, obvious mould or mildew, unpleasant musty odours and strong tobacco smoke odours. Such problems need to be remedied using specialist chemicals and professional cleaning equipment, and it is quite easy to make them worse by trying to fix them yourself. The reasons for this are twofold. Firstly, car manufacturers are increasingly packing more and more electronics into modern cars, meaning that the act of shampooing has become a bit of lottery (professional valeters often have to individually inspect every car to locate any electronics before commencing work). The benefit of using a professional valeter in this case is that they should know what they are looking for and should be able to work safely, plus they are generally insured if things go wrong. The second reason for employing the services of a professional is that they will have specialist wet and dry equipment and steam machines, which enable seats and carpets to be cleaned and dried in a short space of time. In contrast, attempts at home shampooing often leave seats and carpets wet for days on end, which can encourage the formation of mould and mildew, and give rise to unpleasant musty odours.

Another potential minefield is the actual quality of the fabrics and leathers used in modern cars. What appears to be leather these days is often more likely to be textured vinyl, particularly when found on the backs of seats and on door cards. Real leather is often only used on the cushion and upright of seats, and even then it is often quite different to traditional leather. In days of old, manufacturers would take a hide and shave it into three layers. The bottom layer (suede) was discarded and used for other purposes, while the top two layers were used for various parts of vehicle upholstery. However, the modern approach is to swell the hide using a chemical process and then shave it into as many as ten layers using computer-controlled machinery. These thin layers are then pressed and stamped with a leather texture in order to mask any imperfections, and then laminated between a fabric base and an uppermost layer of clear breathable vinyl. In effect, many modern leathers are actually vinyls with a thin layer of leather veneer and require different cleaning methods as a result, in particular the use of water-based cleaners and protectants as opposed to traditional oil-based leather feeds. These issues also extend to the fabrics used in many modern cars, which are often easily stained even by small amounts of water or other liquids. The reason for such staining is not well known, but is most probably due to reactions with chemical residues left over from the manufacturing process. The upshot of all of the above is that we recommend that you should avoid shampooing or making your upholstery wet and take great care with any leather, making sure you identify what type it is and use appropriate products to clean and protect it accordingly. If the interior of your car is already in good condition then the following advice will enable you to keep it that way, meaning that you will probably never need to call on the services of a valeter. We recommend that you detail the interior of your car on a monthly basis and clean and protect any leather present on a quarterly basis.

When it actually comes to cleaning the interior the first thing you should do is brush down all fabric surfaces using a soft bristled interior brush and wipe down all hard surfaces using a dry microfibre towel, in order to transfer loose dust and dirt to the floor area. Brushing really helps to pull fluff and dust out of the fibres of fabrics, and restores an attractive plush look. The next thing you should do is remove the mats from the car and vacuum the carpets and, if they are covered with fabric, the seats. Again, brushing really helps to loosen dirt from the fibres of carpets and restores a nice appearance to the pile. If your vacuum cleaner has a suitable soft brush attachment this can be used at this stage to carefully clean the vents in the dashboard, otherwise this can be done using a small detailing brush. If you have pets and a hair problem to remedy, a rubber hair extractor makes relatively short work of such problems and is an inexpensive purchase.

With the fabrics and carpets now clean, the next thing you should do is tackle the hard interior surfaces, i.e. the dashboard, instrument panel, centre console and door cards. If these areas are only dusty they can be cleaned and dressed in a single step using a good quality surface dressing, applied using a microfibre pad (apply the product to the pad and wipe over, rather than spraying the product all over your interior). If they are dirtier, such surfaces should be wiped down first using a damp microfibre towel. For tackling really dirty surfaces, dampen the microfibre towel with an all purpose cleaner diluted down to the recommended level for interior use. We recommend that the steering wheel is only wiped down with a damp microfibre work towel and not dressed in any way for reasons of safety.

Using a soft-tipped interior brush really helps to draw dust and debris out of fabrics

Loosened dirt and debris can then easily be removed using a vacuum cleaner

Hard plastic and vinyl surfaces can usually be cleaned and dressed in a single step

After cleaning and dressing all of the hard interior surfaces, the next thing you should do is clean the insides of the windows. If they are relatively clean they can simply be wiped down using a liquid glass cleaner and a microfibre towel. However, if you are ever left with sticky residues after removing interior window stickers or have a tobacco film to deal with, both can be easily and safely removed using a dab of methylated spirits and a microfibre towel (don't wash this towel in your washing machine again, instead reserve it for grubby tasks). After cleaning the insides of the windows you shouldn't need to sit in the seats again to finish the job, so the next step in the process is to tackle any stains in the seat fabrics, or if you have leather seats, clean and protect the leather. In both cases, any cleaning can be safely done using an all purpose cleaner diluted down to the recommended level for interior use; if you have leather seats read the label on the bottle first and make sure it is safe for use on leather. In order to use the cleaner you should dampen a microfibre towel with it and then wipe it over the surface, rubbing stains gently. Do not saturate the surface and use as little product as possible to ensure a speedy drying time. Once leather seats have been cleaned they should be protected using a good quality leather protectant, which should be applied using a microfibre pad.

The next step in the process is to clean and protect the door shuts, which are often completely overlooked. If the door shuts aren't particularly grubby they can be easily cleaned using an all purpose cleaner and a microfibre towel - it is worth remembering to give the pedals a wipe over at the same time (using an old toothbrush helps if your pedals are heavily textured). If the shuts are really grubby, they can be washed down using a microfibre wash mitt and a bucket of suds, and then dried using a heavyweight microfibre drying towel. Once clean and dry, shuts should be protected by applying a surface dressing to plastic surfaces and either sealant or wax protection to painted surfaces. In the latter case sprayable products afford a quick and easy means of applying protection.

Liquid-based glass cleaners are preferable to glass polishes, as they do not dust

Cleaning and protecting the door shuts is not difficult if done on a regular basis

A clean well dressed interior is always inviting, even more so in a daily driver

The penultimate step in the process is to tackle the mats you removed from the car during the initial stages of the process. While you do this, you can also do something about any odours in your carpets by sprinkling over either a household shake n vac style product or bicarbonate of soda and leaving it to absorb contaminants for a couple of hours. The latter is the better choice, as it is odourless, unlike household products, which can be a bit flowery. Returning to the mats, the first thing you should do to them is brush them and vacuum them. If they are made of fabric and feel damp after vacuuming, hang them up in a well ventilated place for a couple of hours to dry out. It is a good idea to do this regularly during the winter months, as mats often become sodden at this time of year and regular drying out will help to prevent the formation of mould and mildew, which can otherwise give rise to unpleasant musty odours. If your mats are made of rubber they can be restored to as new condition using an all purpose cleaner and a microfibre towel; under no circumstances apply any surface dressings to mats (or pedals for that matter). If you opted to treat the carpets for any odours, don't forget to vacuum them again thoroughly before finally refitting the mats.

The final step in the cleaning process is to pack away all of the tools you have used, making sure everything is clean and ready for next use. All towels and applicator pads should be washed in a washing machine at a low temperature using a non-biological liquid detergent (avoid soap powders and detergents containing bleach or fabric softeners) before being allowed to dry out naturally. Finally, any fluff and hair lodged in your detailing brushes should be picked out and the vacuum cleaner emptied.