Squeaking/Whistling noise while driving

[landmark]

Hello,

I own a Toyota Aygo year 2011 with 44700KM on the clock.

The car was bought second hand and up until a few months ago, car was working fine. I have recently noticed that while driving I am having a constant squeaking noise and it only stops when I press the brakes. The noise is unpredictable as it doesn't really have a pattern but I did notice that it stops at high speeds (100kmh - 130km) and it's especially loud at low speeds and while parking somehow. 

Brake pads and discs have already been changed but the noise still persists, at this point I am unsure if it is coming from the wheels or possibly the engine bay. Any ideas what it could be?

Thanks :)

[PetrolDave]

Is the noise coming from the front or rear wheels? Have you checked the rear drums and shoes?

[haelewyn]

Listen if it isn't a belt making noise, engine running, engine bay open and you standing in front of it. If it's also making noises while parked with engine on, check all the pulleys.

While driving, roll out in neutral gear, clutch pedal released. This will tell you f.e. if it's a gearbox noise or not.

If only a noise while driving, if the noise is intermittent, I would think about the brakes again. You replaced discs and pads. The moving part on the disk brakes, the caliper, could be to blame too (front).

Of course the back drum brakes could be the cause too.