heres a couple of pics of the bolt you need,the one on the left is a standard (rs turbo/xr3i) alloy wheel bolt,and the one on the right shows the sort you need with the bigger colar!
the second pic i took just for the hell of it to show you wot it looks like without the colar as they come off,however they dont come off on the standard bolts.
some people put the bigger colar on standard bolts say from a sierra or fiesta,but thats dangerous because by the time they have gone through the wheel and disc theres only a couple of threads holding the wheel on!!
shown in the 3rd pic ive put the washer over the standard bolt,now compare it too the pic above.

trouble is i dont know wot car they are from(on the right) does anybody else have any idea?????