Thanks for the feedback
The primer used was Halfords own grey primer. I haven't tried the primer for plastics as I've never seen it in my local shop.
You could have a solution to the problem there...
I've also been using Halfords sprays for years and never had any problems until now and only with these Colours.
The damage is visible after 20 min or so and gets worse as the paint hardens. It seems to be related to the lacquer in the paint as the satin does not react as badly as the gloss. I did get away with a few satin jobs on a Tamiya S2000 once. but it was only on small areas.
Another idea I had was that these paints have a shelf life?? I've only had them for a few months but they could have been on the self a lot longer.
Last thing I want to do is go out and buy another can just to test it
