I think what you may be refering to is paint sealant
. All dealerships offer this expensive option. When I had my detail biz, we would apply this sealant after buffing and full detail. (Late model used cars) I got 80 bucks for doing the complete detail and sealant...they charge the customer 300 clams.
You can buy similar products at any detail supplier. You'll still need to wax every month or so, and reseal every 6 months if you like. A semi-annual polish/buff and waxing every 1 or 2 months is all ya need to preserve a good shine. Before, a lot of black, white and reds had no clearcoat. Without diligent waxing, they will get dry and chalky. I've noticed a lot more of these colors are now clearcoated, still, waxing (not polishing) is important on a regular basis.