I'm not sure if you get Nitromors on your side of the pond,it is very effective but you need to make sure the panels are meticulously cleaned afterwards.

I had some paint issues with an o/t car paint job after using it.
Probably my fault in the end.......

1950 Chevy Advance Design 3100 in Scotland
In the Stovebolt Gallery
More pix on Flickr.
I've definately got this truck thing in my blood ... my DNA sequence has torque settings
"Of all the small nations of this earth,perhaps only the ancient Greeks surpass the Scots in their contribution to mankind" Winston Churchill.