From Jayski.com:

More on the possible Busch Series car change: The Busch Series eventually will have a new car, but not before NASCAR debuts the Nextel Cup "car of tomorrow." The car of tomorrow debuts next season with a 16-race schedule. Full implementation at all track is scheduled for 2009. Any plans for the Busch Series to have a new car won't be decided on until NASCAR evaluates the Cup car. "The main thing is that we take things we've learned from this car of tomorrow project, safety and things like that, and continue to integrate that into the other series," NASCAR Vice President for Pemberton%22">Competition Robin Pemberton said April 20. "But as far as a total tearup of chassis and bodies, we haven't come to a timeline on any of that." There has been talk about the Busch Series using totally different cars, such as Mustangs. "It's in the talking stages right now," Pemberton said April 21. "A couple of the manufacturers have come to us and expressed a desire to look at running maybe different makes in the Busch Series versus the Cup series. I think that's a pretty good idea and we're looking at it."(SceneDaily.com), past news about this on the Busch Series site.(4-24-2006)