hey guys car is making a circular grinding noise from the rear only when reversing and just today in stop and go traffic the cars brakes feel as if they are being applied slightly when my foot are off both pedals. Could this be the e-brake line, abs caliper or worse the tranny?

 

Sounds like the park brake shoes. Remove the calliper and rotor. You will need to back off the park brake shoes by using a small flat head screwdriver in the backing plate to rotate a cog wheel, and inspect the shoes for the park brake