100 MPH in my old Pontiac Grand Prix on the interstate through my city. (night time, racing some girl back to our neighborhood home from work. her honda crv couldn't keep up after 90mph.) and yes i know that's a dangerous thing, but only to myself in this case, as we were the only 2 out that late on that interstate.
and i've been in a car going 110MPH, but i wasn't driving. it was my friend's Ford Taurus, and we were thought it was cool when it hit the speed limiter 8)
once again, this was really late at night on an empty highway. but we were in a hurry to get back to our college town so we could sleep. (they had picked me up 2.5 hours from our college when my grand prix broke down. got back to the dorms around 2:30am.
)