There are various reasons why moisture can occur in a car. You bring it in on shoes or jackets, or it enters the interior of the car in other ways. What you should do if your customers ask you to remove mould or water stains can be found here.
It is important for your customers to know why moisture occurs in the car. So the best thing to do is to go through with them to find out why: Is the air coming from the blower humid, or does it even drip from here to the floor? Then it is very likely that the rain drain between the windscreen and bonnet is clogged. Pay special attention to this area when cleaning!
If there is a smell of mould in the car when you open the door, you should take a closer look at the floor. Press a cloth against it and see if it is saturated from below. If so, it may be that the underbody is damaged and the water can penetrate from here. If you exclude another origin of the water with your investigation, your customer needs to take their vehicle to the garage.
However, you should first examine the seals of the windows and doors. If these are porous, they also let moisture into the interior. If the car has a roof antenna, its mounting can also be a weak point of the car, through which water may penetrate into the interior. The same applies to the roof of convertibles. If you suspect technical defects such as a broken pipe to the rear window wiper or damage to the radiator, only the garage can help.
Water stains can soon appear in a car. They are caused by the lime in the water. If your customers clean their car seats at home, water stains can occur if they wipe with clear water at the end and let the upholstery dry on its own. You can remove such water stains from car seats by carefully cleaning them with a steam cleaner and wiping them over with a microfibre cloth. For leather seats use a leather care product, for suede seats use a suede brush.
Many of your customers will have already tried at home to use household remedies to combat mould in their cars. Even if this is not the case, they expect you to do a professional clean. Accordingly, use a professional anti-mould spray from the manufacturer you trust. If you need to treat upholstery, it is best not to use any products containing chlorine or alcohol. These can bleach the fabrics and then the customer won't be happy. It is better to use a spray whose active ingredient is quaternary ammonium compounds. It won't damage the upholstery. Always follow the manufacturer's instructions exactly when using the product!
If you notice that the air conditioning system is affected by mould, you should refer your customers to a specialist. Not every garage has personnel who can properly disassemble and reassemble an air conditioning system. As a general rule, the mould will return if the cause is not eliminated. Point this out to your customers so that they actually do something about the moisture – otherwise they will back be on your yard with a new mould problem all too soon.
Instead of simply removing water stains and using spray to combat mould, you should help your customers find the cause of moisture. Although the removal of stains and spores does help them, it only lasts for a short while. They will remember you better if you can help them in the long run. If you impress with your expertise and give helpful advice to customers, word will get around. And then people come not only because of the car wash, but also because you really know about cars and can help with everyday problems.