I on my third MBZ, one CLK, S420 and now an 01 S500. Enjoyed the first two immensely. Like the 01 even better. My dilemma: the Bose audio system does not automatically increase the volume while increasing driving speed, the low end bass performance seems woefully inadequate compared to my last S car, the amp works and all speakers are working, even the sub - just poor output from the sub. I even put the fader 90% to rear to help compensate and it only helps slightly. Doesn't matter which ambience I select. A repair shop for these amps claim a software upgrade may be in order - is this so? No typical pops, clicks, humm from any channels normally associated with a bad amp.

Answers would be greatly appreciated.