I have a 97 E320, and just took it to a stereo shop to get a sound system installed. They pretty much spent the entire day and installed a deck two amps, two 10' woofers and a set of speakers inside the car. By the time they were finished they went to start the car, and it would barely idle. I then towed it and took it to my mechaninc, and the results ended up being that my computer was fried. Anyways, I still wan't the sound system to be installed in my car, and obviously dont want the same thing to happen. Can anyone give me any tips to why this happened, and whats the right way to install it on a 97 e320. I heard to leave the negative on the battery unplugged and the key outa the ignition. Any other tips or hints would be greatly appreciated.