Clay bar, never used them till last year. Now I love clay bar, just preps paint for a polish removing dirt and grime you can't see. But you will see the difference when done. No need to worry about scratching, they don't and easy to use, spray lube and away you go. Not the best at tar removal, but when you run your hand over the car and it feels rough clay bar takes the rough away ready for polishing. If you never used before, once you have you will always use ,.......