I just took possession of my 97 M3 5spd with 64,000 miles on it last night. Well, I'm not sure if this is a problem or if its just he way the M3 is, but I hear and feel a loud exhaust type noise when the car is about 25 mph. For instance, if i'm current at 40 mph and then the car slows down to about 25 mph, the exhaust noise gets louder. I told my wife thats just how the M3 is suppose to behave. Is this normal for these generation M3s. This is my first M3 so I'm not sure whats normal and whats not normal. Its not a bad sound or anything... but it just gets louder when it's at 20 or 25 mph. Please advise.