Restoring dull bodywork

[oldagetraveller1]

I've just bought a 14 year old Rapido 779m motor home. The bodywork is undamaged but dull/flat.
Ordinary polish doesn't make much difference. The material is apparently 'Polyglace', a white polyester.
Has anyone successfully restored a reasonable finish to this material?

 

[Dustydog]

http://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/GRP-or-not-GRP/30583/
Plenty in this thread to keep you busy.