can I use my pre-qualification for a classic muscle car

I would say probably not. Finance companies don't look at vehicles as collectables. They look at them as a commodity that is used, ages, and discarded for a newer model when they wear out. It becomes more difficult to get financing for a vehicle as it passes the 6 year mark. We literally had a person on this forum asking how to finance a 1970 model collectable vehicle last week. They couldn't get anyone to finance the vehicle even though they were preapproved. A personal loan, home equity loan, or other unsecured loan is the way to go with something like this. Hope that helps! Jim