Yahooka00

First time benz owner and new member. I purchased a 2005 c230 kompressor sport sedan (M271). 2nd owner! First owner was little old lady no joke only put 55,000 miles on the car. Great condition. So my question is it has pretty much every option on this car, but how do you tell if it has the harman/kardon upgraded stereo system. I can't tell. Any help or any advice about the car would be great. Previous owner did everything her advisor told her to do. (Trans service, coolant, brake flushes, spark plugs. I mean everything.