Took the 328 out the other day. Warmed it up well and did some high rev shifting over the course of about a 30 minute drive. I was just about to go back to the house and gave it one more (fairly) high rev shift into second and I hear a whistling/whining sound as I goosed the engine up to about 6500 rpm. The sound went up and down in pitch along with the engine revs. Noise went away as I gingerly drove back to the house. Car runs fine and I didn't try to push it again but... what the hell was that!!