During one mission, after ditching my Bobcat because one of it's rear tires were blown and handling was atrocious, I was running down the middle of the street with a 3 star wanted level, and this cop car came roaring down the street and just as I was going to run to the sidewalk, the cop car swung around into a skid. The car impacted with Niko and killed him as it sent him flying.

During another mission I stole this Dodge Viper look-a-like while a guy was looking into the trunk, and once I took off the guy was holding on to the back of the car. He got thrown off during a high speed turn.

I also found a very nice car that's hidden. You can hear nitrous as you shift gears, and occasionally fire will shoot out of the exhaust. You must have the last island unlocked, Alderney I think it is. Go to the map, and zoom in on the top right hand corner. You will see a road that branches into 3; take the middle one as it ends with a large, run down house. Next to the house is a garage, go behind it and sort of hidden in the bushes is a Sultan RS.