[Greem]

I'd never heard of this purple pole thing but it turns up on a few websites, the most notable of which is Forix.

It was a manifestation of the Purple Pole syndrome. As one mechanic put it, "This bloke Stewart's been winning and we've all got to pretend it's something on his car, so we copy what he's got. If tomorrow he came along with a long purple pole stuck out the front of his car, by next week we'd all have long purple poles as well!"