OP, as it won't be an easy fix can i suggest you pull/scrape some paint off the effected panel and try to see which layer the cracks are in. I've got a feeling it will be the clear, i've got no faith in 1K clears as the technology is so old. Also did you use an acrylic laquer colour or a true base coat which requires 2 pack clear over the top.
I've got 27 years experience in the car painting industry and to be honest i've never come across that situation.
I've taken the paint back to bare metal with an electric sander and the cracks are definitely in the clear coat layer. I have no idea if its a true base coat or not, I trust the guys who sold me the paint to give me the correct clear coat for the job. There's no way I could use 2K paint with the facilities I have, if its impossible to paint metallic with 1K clear coat then I guess I'll have to save up and leave it to the pros.
