This happens all the time in my CTS-V. For some reason, every jerk with something to prove wants to race, or slowdown, or somehow aggravate me. A guy in a supercharged Hummer floored it as I was coming up on him. He tried to ace in front of me into my lane. As he hit the gas, and his Hummer began to shudder like it would explode, I downshifted from 5th to 3rd, left a little tire behind, and let him know that he should pick on something like my Escalde instead.

Every Corvette, juiced ricer, Mustang on nitrous, and any other manner of car you can think of does that.

Part of the territory I guess.

Maybe some day I'll find an X5 that wants to race.;-)