Last weekend at our local school we had mishap with a BMW using extended lugbolts and wheel spacers. Turns out the nuts were only engaged about a single mm. This is what happens when you don't fully engage threads.

http://www.cashmo.org/2005/05.atlant....dsp.wheel.mpg

I use 15mm H&R spacers myself and you bet I'll doublecheck the installation and thread engagement.

 

yech....that's not pretty.....

with over 10mm spacers, it's generally a good idea to put in longer lugs...

 

Wow... not good. Was that the spacer ring that flew off after the wheel?

 

I wasn't there but sure looked & sounded like it.