He wedged himself in the gap and proceeded to push his way forward as if I wasn't even there. Another time I purposely ran into a car at an angle and was dismayed when he didn't budge. About the only way to cause cars to slow down is to get in front of them and let them hit you from behind, which they do often. Which brings into question the AI of the cars. Some races I'll get hit multiple times from behind.
Real racers are smart enough to slow down to avoid accidents.
Even when I'm behind an AI car and slow down to the same speed I' ll occasionally get whacked from behind.