I just purchased a 97 E420 from my brother. He always had it serviced at the dealer. He also had it tuned-up as part of the deal. I test drove this car several years ago when he first purchased it. As I can remember flooring the accelerator pedal on the expressway and feeling that burst of G-Force acceleration pushing me back into the seat, just like you would if you were in an aircraft. I was testing it again on the expressway since it was recently tuned-up, but that burst of power was not there. I'm thinking that the dealer did not do a good job on fine tuning this car. Am I missing something? Or did they do a lousy job? Can someone give some advice on repairing this problem?