Ok now for some science behind the buell painted platic airbox cover.
Paint for plastic is different to paint for metal. This is because paint for use on plastic has an added
flex agent which allows the paint to move with the platic without cracking or delaminating. Great.
However, this means that paint for plastic is softer than paint for metal. This is because when the flex agent is added it is like adding loads of tiny little particles inbetween all of your paint particles. These microscopic pockets in the paint allow it to move but also make the paint softer, more porous, less resistant to staining etc. But the main problem for us is that you cannot buff the paint.
If you try to buff painted plastics this will cause the paint to smear rather than to bring out the gloss shine.
The only way around this is to maintain the finish on the paint from day 1 with a good quality polish, a good quality cloth, and lots of elbow grease (no machines allowed I'm afraid).
Which brings me back to my original question, which is the best quality polish you can buy for painted plastic
Lol - no need to reply, I just wanted to share the knowledge I have managed to glean from the interweb