Hi. Exciting experience. i had a chance a couple of days ago to race with s4 at night around 1 am. i was driving 75, and a car came right next to me, and made a couple of idle crush. i soon realized that was a black s4, and he wanted a combat. i signaled him, and we were on. i kicked down one gear, and suddenly he couldn't catch up with me. after i hit 135, i noticed that the car is hesitating to go any faster. and the s4 was suddenly cought up with me. i slowed down to 110, and he did also. we started again, and we were almost same to the end of freeway 110. i know this is dangerous, and could be deadly. but, i did not want to escape from s4 people. ha ha ha.