First question…paint or gel coat?
Assuming gel coat, I’ve had great success with Meguiars line of boat polishes and waxes.
This link is to Meguiars boat/RV page. I do not use the “premium” line. I use the standard line of products (in the blue bottles), just click the polish and wax links on the left and look around.
The Classic Roadsters Duchess in my photo gallery is 25 years old (pmossberg gallery). It’s the original red gel coat from Classic Roadsters.
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica Roadster
If you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)