I was surprised at how well this worked! Cost $10 at a local auto parts store, took maybe 20 min to apply, result was very, very good. I only expected a mild improvement from the old crappy look, but this went from 17yo yellow, scratched-up lights to clear lights that look almost new. I had tried the toothpaste method a few years back and it was barely noticeable and took much longer. I wish I wouldn't have waited until I was ready to sell to try this! The kit is for one car, but if you had them parked together and were working efficiently, you could easily do the lights for two or three, I bet. The limiting factor are pads for sealant that can't be put back once opened.