Remove floor mats and clean car inside every three months (if necessary, do it more often). Vacuum upholstery and rugs to remove any remaining dirt and dust.
Leather upholstery requires special attention. Stains should be removed with warm water and a very mild soap solution. Use a clean cloth to remove the soap and then wipe the upholstery again with a dry cloth. Never use alcohol, benzene, nail polish remover or thinner to clean leather upholstery.
After cleaning, treat the leather upholstery regularly with special wax. Never use car wax to polish leather upholstery.
Where the car's interior is exposed to sunlight, cover the leather seats with sheets if the car is left in the sun for any length of time.