Don't know if it's coincidental, or related...but my noise goes away when the interior lights go off a few seconds after you take out the key. I always thought it was some sort of capisitor or relay noise.
<span style='color:green'>1994 325i </span>- - - 75,000 mi.
No mods - - - very happy as is!
<span style='color:green'>1995 525i </span>- - - 154,000 mi.
No squeaks or rattles... unreal!