Part of the problem is that they self tighten as you drive. Painted wheels are more of a problem than stainless ones as the paint finish tends to “grab” the wheel nut / spinner.
I had always understood that the spinner would tighten to the correct torque and not too much. Quote from MWS:
"Apply the spinner by hand and tighten 3 to 3½ turns; give the spinner a couple of taps with the hammer; lower the wheel to the ground and give the spinner a couple more taps.
As long as the hubs are fitted correctly then the spinners will self-tighten and lock as the car is driving.
If you hammer the spinners too enthusiastically then you will deform the thread of the spinner and the hub and they are more likely to work loose.
Over-tightening also means that if you ever need to replace either the hub or spinner then you will also need to replace the other part as the deformed thread of the old part will not fit with the new thread."
