It appears to me that maybe many of us would have less electicial problems if we just remove the 4-color navigation DVD player, the 6-CD player, the command unit, and finally Bluetooth. I really do not understand Mercedes doing this setup for 2007 and earlier models. Just image how much electrical power we can save and how much less of a drain on our batteries with one of the new Navigation systems that has all of the above built into it and consumes less power. In 9-months my warranty expires, and I think I'm going to make the jump to a pioneer or Kenwood all in one unit. I have checked the prices for a replacement command unit and it ranges between 6,000 and 10,000. For a customer installed between 3,000-4,000 dollars. I undertand that some of the SL500 controls on the steering whell will not work but so what. The problem now is finding a good car stereo shop/installer.