Ginny, Just a few more thoughts. If you power brake the car (trans in drive, foot on brake, and slowly floor it) does the noise get louder? Also, have your daughter rev the engine up while in park while you check the exhaust flow out the rear...could be a restricted exhaust if you're not getting a strong flow out of the mufler when engine revs.

__________________
82 300SD 202K
82 300SD 233K
83 300TD 340K
82 300TD 98k euro (parts on the hoof)
85 300TD 282K
83 300TD 197K