I was going to be flippant and say great minds think alike, but actually I am glad to have confirmation that I'm not talking rubbish. I haven't done car paint repairs for a awful long time and I was never very good at it, particularly as I did not have a garage to keep dust and rain off. I have however painted a few railway carriages and can now get quite a decent finish with roller and brush. We use etch primer on aluminium panels very successfully.