I bought it about a year ago, and I guess I did wax it once, but that appears to be the only time it has been done. And now it badly needs another coat or four... Being it is a minivan and has been around kids, it has a lot of scratches. So, what product would work to remove those scratches and seal/protect the paint? The van sits out most of the time, and is exposed to salt and other winter elements quite often. Thanks!