Years ago, I used to regularly wash and polish or wax my vehicles. I got lazy and now only wash. I can't tell any difference. It seems regular, GENTLE washing with a good quality wash is the best thing you can do. If anything, a good, long-lasting wax can make the road film and bug juice a slightly easier to remove during a wash. The key is a gentle, frequent wash to avoid damaging the paint in the first place. Once the paint is damaged, all you can do is temporarily cover it up or remove a little clear coat through aggressive polishing. Unfortunately, you can only do that a limited number of times before all the clear coat is gone.