i had what I thought was a wheel balance problem when I collected my car. It was fitted with some 15" AEZ 5 spokes, but it wasn't until I got the wheels balanced that one of the tyre fitters pointed out o me that they where missing. As I have had a wheel come off in the past due to it being from another car and not locating centrally on teh hub, it was a little worrying. It cost me a ?10 for the new ones, but I had to phone around, the likes of halfords didn't want to know. Good luck,
Craig