Fold the rear seats down and the noise increase is obvious, basically the same as removing them. Try that to see if you can tolerate the sound. The seat backs remove in a few seconds once you figure out the process. You have to tilt the seat down, push the seat back towards the outside of the car, and lift the pin out of the slot next to the door. Very difficult to explain, easy to see when you do it. The seat bottom isn't worth the hassle to remove for weight only, it's a pain and only about 10 pounds.
SparkE wrote:What is "noticeably better acceleration" ? (specs, please)
10-60 mph acceleration reduced by > 0 % and < 3 %, +/- 1%.