I also have an annoying exhaust noise in my GLE 350 that I purchased in September and have approx. 2,500 miles on it. The noise appears at 1,500 RPM and goes away between 1,800 and 2,000 RPM, took it to the dealer and they said that it was normal. Also, I have a situation where the revs increase (blip) up about 500 rpm each time the transmission downshifts. I have had 3 MB's before this one and they never did it. Told the dealer and they also said that this is normal. I am wondering if my noise and rev issue is more related to a torque converter problem instead of an exhaust issue???