Auto Appearance Directory - But by far, the most important thing for the auto appearance specialist when choosing a paint is this: you must use an auto paint system when you paint your car. That is all of the material, primers, sealers, surfacers, base coats, clear coats, reducers, thinners, hardeners, etc. must all be of the same manufacturer and compatible with each other. This is why you need to consult with a paint supplier as to what is right is right for your car. This is why you can't primer your car with Autozone's sandable auto primer (on sale for $1.99 a can!!) and spray it next year with God-know-what brand auto paint you haven't decided upon yet.