Hi Robert:

Could it be your fuel pump? an SL owner describes a whine from the rear of the car in the following thread:

http://www.peachparts.com/shopforum/showthread.php?threadid=7902&highlight=whine+fuel+pump

__________________
John

2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)

Click to see 87 300E