Casey Mears' stint as the replacement driver for Brian Vickers in the No. 83 Red Bull Racing car is over. Mattias Ekstrom is driving the car Sunday at Infineon Raceway, and RBR announced Reed Sorenson will drive next week at New Hampshire. "Our unique situation has afforded us the opportunity to try some different things, and we're continuing to do that with Reed," RBR general manager Jay Frye said in a statement. "We appreciate Casey's work and everything he's done the past five weeks." The decision to drop Mears was made a few days after Mears' run-in with teammate Scott Speed at Michigan; Mears also later collided with Roush Fenway Racing's David Ragan in the pits. http://sports.espn.go.com/rpm/nascar/news/story?id=5305426
