I just thought that I would resurrect this thread really was intrigued to see if any of the suggestions worked, well okay I tried one... Tracking down that pesky Novus super polish is a bit of a trek, yet to find any sold at a UK online retailer, haven't got round to ordering from overseas yet, surely there is a similar substance found here?
Sooo the next suggestion toothpaste...
I dug out a suitable candidate, an old McLaren stripped of decals, however the number roundels had been previously removed leaving a white circle on a yellowed body.
Scrub, scrub, scrub away I did... is this a wind up? After a good few minutes there appeared erm, diddly squat difference; apart from some faint surface scratches where the tooth paste has attacked the plastic.
Ahhh, please remind me again... How much scrubbing is actually required?
I always previously thought that the yellowing was more than surface level resulting in permanent discolouration? Otherwise if it is just surface level as this thread suggests, it could in theory be rubbed off?
Also, the yellowing/browning effect common on old cars is caused by old tyres?