Sorry hcarter, forgot to mention, I'm in the UK. I found these on ebay:

MERCEDES W203 15mm 66.6 ALLOY WHEEL SPACERS + BOLTS on eBay (end time 03-Sep-10 17:21:47 BST)

called the guy up and we got into a discussion about thread lengths his are 40mm threads and he believes they will fit no probs, however in the picture its clear the lug bolts have a tapered seat!

I was just aout to purchase the 55mm bolts from ebay as per your previous post and now this guy confuses me even more!

if our bolts are a 40mm thread as standard then I need a 55mm thread with a 15mm spacer - right?