Yep, Wheels Around drilled out 3 of them and the rest came off with a bit of persuasion. Bimecc is the company that make the bolts and the keys for the S2 and I think that this: http://www.priracing.co.uk/product.php? ... e9a10afdf9
is also an alternative to the standard key. However, I didn't waste my time ordering any more and just switched to a set of standard 17mm hex bolts.