I know they are not Gen VX parts but they fit the bolt/wheel so much better than the VX ones.

http://cgi.ebay.co.uk/ws/eBayISAPI.d...MEWN:IT&ih=019

Only problem is they dont fit over the standard vauxhall lock nut heads, about 1mm too small They could be modified to fit I guess.

Dont know about after market wheels but they fill the snowys holes perfectly and maybe painted silver to match would look even better.

Pics to follow.