2003 Acura RSX Type S 6 speed manual with 65000 miles. There is now a whining sound coming from the rear ONLY when in reverse gear AND stepping on the brake pedal. No whine when just in reverse. No whine just stepping on brake pedal. Only the combination of the two creates the loud whine. Any ideas?

 

Usually brake wear indicators are installed to work in reverse. Take your wheels off and check your brake pad thicknesses