May want to poke this question over in the "Car Audio" forum if you don't get any replies here. In fact you may want to do a search over there for 300E and 300D cars of your year/body style.
http://www.peachparts.com/shopforum/forumdisplay.php?forumid=10

__________________
past MB rides:
'68 220D
'68 220D(another one)
'67 230
'84 SD
Current rides:
'06 Lexus RX330
'93 Ford F-250
'96 Corvette
'99 Polaris 700 RMK sled
2011 Polaris Assault
'86 Yamaha TT350(good 'ol thumper)