Detailers should alert customers to the dangers of selecting the wrong cleaning chemicals for use on or in their vehicle. Washing with household soaps, or choosing to use a specialized product for general cleaning, can lead to problems.

Today, soaps and cleaners are created specifically for vehicle makes, models and years.

"Tell them to never use dishwashing detergent because it can strip off wax, and never use vinyl cleaner on leather or vice versa," explains Mike Pennington, director of training at car-care products maker Meguiar's. "They also need to make sure the products they’re using are formulated for the particular year, make and model of the car."