I did a Track Time open lapping day at Watkins Glen in ~1993. On that particular day, the track had also been rented by a Busch Grand National North team, whose driver at the time was Steve Park. During the driver's meeting, the chief steward said to not bother giving the race car a point-by; just watch your mirrors carefully, hold your line, and he will find a place to pass.
Yeah, no kidding! He passed me on the backstretch at an obscene rate of speed. Basically, I saw him in my rearview mirror in time to see him disappear off to the side. The exhaust from his car was so loud, it made my ears ring, even with my helmet on.