Wtf??

Just got the car back from service department and on the way home i hit some traffic on a part of the bridge. I weave in and out of lanes and when i get ahead of "the rolling road block" i give the Q 80% throttle and the car takes my smoothly and quickly up to 115.I slow down to 90 and this Bmw X5(3.0) flashes his lights at me so i politely move to the right to let him pass. But no he has to be a real jerk off and starts taunting me up hit in the gas and releasing and hitting it again. So im just annoyed and decide to flex some muscle so i give her 80% throttle again and im off, 100, 110, 115. I dust him to 115 but hes on my next to me again so this time i decide to test the truck and put my foot down again(80% throttle) so at 120 the car isnt goin any faster so i think "hmm odd" and floor it. I just floored and the car fails to react and im stuck at 120 with my foot welded. I was really pissed off (laughed gave me the finger and took off. Last time i raced a x5 (4.4) the Q got up to 130 with a bit of trouble, but it got up to 130 at least this time the car was not going faster than 120. I have a feeling that service dep might have done something. Anyone know where to go to get a speed limiter taken off?