I have been using Poorboy's World EX-P Pure Sealant with good long lasting results. The good thing about many of the sealants is you can add layer after layer and build up a nice thick coating on top of your paint to protect it from acid rain, bird poo and the like. If you have swirl marks and want to remove them, you'll need to use something with some "cut" to it to remove the swirls 1st. Check out a place like
autogeek for more info on paint care.