Does anyone know the best method to restore the colour (paint??) on Japanese import plastic parts such as bumpers?

With my grey (colour code 182 "bluey grey mettalic") st185 rc (project arsey) having been gathering leaves and moss for the last 7 odd years the metal paint has survived pretty well but the plastic parts that are body colour now have a Matt finish.


My concerns are that I have vague memories of some cars having painted plastic cars and some that were coloured plastic and if the process will be any different?

My standard practice would be to give it a good mopping followed by waxing for paint.

Any thoughts?

_________________
JP
GT4DC Treasurer

Grey St185 RC
Silver BMW E46 M3
Multicolour yawn Honda VFR400
Silver Honda Civic Type-R