mine were from toytuning, dunno if they sell them anymore though (probably coz they discovered they're WANK!), the ones on their website now look more durable. It seems theres been some kind of welding between the two dissimilar metals so now theyr'e stuck. Then when you try to turn them the bit your trying to turn snaps clean off!! leaving you with the chamfered fucking boss still gripping your wheel on but with nothing to grip ARGGGGHHHH! how did you end up getting them off?? the only thing I can think now is drill through the nut, down the centre of the stud (with a drill bit the same size of the stud) effectively getting rid of anything for the nut to grip onto. Do it with ALL the other nuts/studs, remove the wheels knock out the studs replace all the studs with new ones and put some decent STEEL nuts on haha!