Hi Joey:
Give Rick Reus a call in California at 1-800-276-8865. He specializes in aftermarket Mercedes audio solutions. Basically, he takes the area where the first aid kit is and turns it into a subwoofer system. I have it in my 190 and it makes a great improvement in sound quality! I don't know how much the system costs, though, since it was already in the car when I purchased it a year ago- but I know it will run you a few hundred bucks. Hope this helps.