No dot problems. We reclassified them as RV's before we left to get out of the no cdl issue. As for mechanical problems it was interesting. They are in good shape but the maintenance was neglected because they where taking them out of service. We had heating problems water leaks oil leaks trans leaks. The Tran no shift light would come on one of them some times. And if they got low on water the computer would kill the engine. It was a learning experience to say the least. But over all they where a good prices and in good shape mechanical considering they are city busses going out of service. But would I do it again... ... ... . probably not.