Tell the general manager to make it right or you will picket his dealership! Also, tell him that you are going to write a letter to the editor of the local newspaper outlining how they sell cars using deceptive business practices. How could the car be "certified" if it is in the condition in which you describe?
It may depend on the state you live in. I know some states, like North Carolina, have a no lemon law. In any state, you have a few options. You can file a complaint with the Better Business Bureau. If this is a chain dealership, ask for the contact information for the corporate offices. They have to provide this information (at least they do in my state). It can also be found on their website. While filing a complaint might not do much, it could encourage the manager to speak with you if you let them know you have filed. You can also place poor reviews on sites like Google (if they have a local page for your area) or other local review boards. I agree with post 2 that the handle and the radio might not be proof of a bad car but the zip ties is certainly proof that they knowingly rigged the car. If you know a local lawyer, you might want to give them a call. You may find a lawyer that will take the case for a percentage rather than a fee. I would certainly let the dealership know that you are serious about this issue. If waiting in the lobby for 2 hours isn't going to get their attention, it might be time to let them know you have filed an official complaint and are going to speak with a lawyer. They certainly knew they sold the car with zip ties on it and they need to make that right.
I am sorry to hear about your situation. I can't imagine how frustrated and manipulated you must feel right now. If I were in your situation, I would definitely seek out the services of a lawyer. There may be nothing that can be done, but I would try. I don't think there is anything that can be done about the car being bad, but the zip ties could be proof that you were swindled. The dealer could claim that they had no idea the radio would go out or the door handle would break, but rigging the breaks with a zip tie could prove they misled you.