I think this is a common issue. Mine were tightened twice and came loose again both times after a weekend at the track. Some shops recommend loctite. Street driving probably makes them loose, too, just that it probably takes a lot longer.

It's kind of annoying, but not hard to tighten them as part of a pre and post track cleaning/inspection.

 

racer63 I had the same exact problem after the M030 Suspension was installed on My 01'. It was exactly what you described it sounded loudest over speed bumps. After it was corrected the problem never occured again.