I have this terrible squeaking noise that only occurs when Im in reverse. Its so annoying and I need help figuring it out. Its more like a tiny train horn noise and I cant tell where its coming from.

 

Noises are tough. Some questions to determine.

Is noise originating inside or outside? Is noise from front or rear? Is the noise made every time you go in reverse or only on first cold start?

Brakes would be a good place to start as there are many components that can lead to squeaks and vibrations. Some are senstive to direction of rotation.

good luck

 

Inboard brake pads have a metal tab that scrapes against the rotor when the pads wear down. When they JUST BARELY begin to rub, they can make all kinds of strange (almost musical) sounds. Wait awhile for it to turn into a screetching sound.

Or just check your brakes pads whether they're near worn-out.