Yea it is wierd, i did them up as tight as i could with a wheelbrace with the car on the ground then got straight in and drove off. There were no noises/ vibrations before it fell off either. All four wheelnuts and studs are perfect still, they are the long type that screw into the rim eg, there is a large gap between the studs and actual wheel. It was on main north road coming up to regency road. Im still going to blame the spacer, may have even cracked it doing it up?