Hey do you all know if there are any problem areas I should be concerned of on this model when it comes to cleaning the engine bay? mostly domestic cars and no problems. kinda nervous with this one.
Nope. No real problem areas. I think 2001 was the first year of the S54. I pressure wash mine all the time - no problems (E85 S54)
You may want to stay away from this box:
It has a huge wire junction, fuses, and relays under it. I think its on the rear drivers side of the engine on the E46 M3. However, I've never had any issues. I've had multiple BMWs and have pressure washed the engine compartment without problem or covering stuff up.