Took a used car for test drive stock # T17468T wit...

Took a used car for test drive stock # T17468T with the salesman. Noticed a humming sound coming from back of car. Salesman acknowledged that there was a sound and said he would talk to the manager. Manager refused to acknowledge that there was anything wrong with car without even test driving the car and said they will not fix anything in the car. On top of that, the car is being sold as is. Dealership is unwilling to work with customers and is unprofessional.