Since there were only a few more than 6000 total E300 Turbodiesels (only made 98-99) imported, there isn't much of an aftermarket for them. I also don't speak German so I can't really search germany's web sites to see what's out there. That said, yes I've done a few upgrades
It's hard to explain how smooth the engine is. It makes the TDI seem like a cummins as far as vibration/noise is concerned. It's a ton faster as well. So far the list includes:
Hella full Xenon upgrade(same as oem xenon, hella makes them)
6disc changer
20% tint
CCV re-routed to the ground/elephant hose (car is only used in warm weather)
AMG Avantgarde tail lights
Full Carlsson Body kit (full front/rear bumpers, side skirts)
H&R sport springs
Bilstein sport shocks
18" AMG Monoblock wheels on sticky Toyo T1S tires
Speedtuning+42hp/60tq ECU chip

Hella full Xenon upgrade(same as oem xenon, hella makes them)
6disc changer
20% tint
CCV re-routed to the ground/elephant hose (car is only used in warm weather)
AMG Avantgarde tail lights
Full Carlsson Body kit (full front/rear bumpers, side skirts)
H&R sport springs
Bilstein sport shocks
18" AMG Monoblock wheels on sticky Toyo T1S tires
Speedtuning+42hp/60tq ECU chip