Adrian Gosling (http://www.speedlinemodels.co.uk/)
Adrian suggests using a product called Plast 'X' 4 from U-POL . It comes
in 400 ml aerosol cans and can be found in two different textures, fine
(Plast 'X' 4F) and coarse (Plast 'X' 4C). The product is normally used
for fixing plastic car bumpers.
Here are a few useful links:
Plast 'X' paint
Plast 'X' paint technical data sheet