Im having the same problem. I used Omni MTK single stage urethane on my Charger. Its been a little over a month since I painted it. I wet sanded and started buffing.....but seems like any time I touch a buffed area seems like it scratches easily.
Most folks look at it says it looks great, but its about to drive me crazy. Im just about ready to sand it and repaint with a better paint.
Another thing I hate about Omni.....its thin as water too. I have heard people say over and over again, that the savings isn't worth it. I guess I learned the hard way, I will never buy this junk again.
1969 Charger R/T---1973 Rallye Charger