These were the 17inch option, I understand. Problem is that the 21mm studs are so wide in the wheel that a socket doesn't get in far enough to make for a decent grip. Result is rounded studs and big problems getting them out.
I know that a 19mm stud of the right profile exists, because my local garage managed to dig one out, but nobody knows were it came from.
Any ideas where I might source 19mm studs fro the st170?