Today was the first time the side collision avoidance (not warning) activated. I was driving behind a bus in the right lane, decided to change lanes to pass him in the middle lane. As I'm about half way through passing him, he starts drifting into my lane, and then abruptly back into his. During his drift into my lane, my car sounds a quiet alarm (not like TACC, where it's very loud) the right rear sensor turns orangish-red, the steering wheel (I was driving, not AP) turns hard as if AP is engaged, and the steering wheel moves the car SLIGHTLY to the left away from the bus, the steering wheel goes back to normal. I was in no danger of an accident (unless he kept drifting into my lane). At first when the steering wheel got hard and moved every so slightly, I didn't realize what's happening. But it quickly dawned on me. I guess I expected the collision avoidance to be more... abrupt? Like a hard pull to the left away from the bus if the car thought she was in danger. Anyone else have experience with this? Was your situation similar or different?