Did you know that the "F" in the F-100 doesn't mean Ford. It actually means farm.
Also the "Ford" logo on the truck is actually the founder Henry Ford's signature.
Is it normal for the car to shake when you are simply starting the engine? I am able to make it start after the second try but even on the highway there are times when it will suddenly just shake.
Does your Fiesta have that sound even when you have bought it?
The next question is if you are sure that the sound is coming from the engine? It is possible that (Just as salah has said), the sound might be coming from holes or dents in the door, window or even the roof.
Tell me if the mechanic has been able to fix it. In any case, I am sure it is a simple thing for them to fix. You might want to check the actual antenna as well if there are any dents, cuts or rust.
A friend of mine was asking me the other day what might be the problem with his expedition. The thing is there are times when the car will pop out of reverse. This is the first time I have encountered this and I am hoping I can get the answer here.
Jailer, check on the following for us to determine where the problem might be coming from:
Check Fuel
Check Battery
Check wiring between Battery and Starter
Inspect fuel system. (You have to make sure that the fuel is actually reaching the engine)
Check if spark plugs are working fine.