When I was test-driving the first car I bought (and still own), which is a 1.8-litre Ford (it's known as a "Ford Laser TX3" here in Malaysia, don't know what it's known as in other parts of the world, if it was even available... it was a classic "underground" car back then, which was early-90s), I went up to 170kph on a highway, with the owner/seller of the car gripping the passenger seat. I wanted to go faster, to approach the limit (which would be about +/- 200kph) but I decided that was enough. This was the fastest I drove a car.