Check this thread regarding the strap, sounds like there may be more than just the one on the exhaust :
Exhaust ground wire - Bimmerfest - BMW Forums
Mine was def not rusted, it looked torn off or cut as mentioned in that link. Btw I looked and it's not a foot long, only several inches.
For you and Big Billy, I snapped a couple pics under my X5. One of the strap, one of the module bring discussed.
Well I am unable to re-size them on my phone, so will do so on my pc later and upload here.