Rear brake issue golf tdi

I recently noticed when I apply the brakes there was a clicking/popping noise coming from the left rear. I took the car in and it was due to a warped rotor. The brakes and rotors have about 10k miles on them. I put a new rotor and pads on and while the car was still in the air I spun the tire and I could hear the caliper catching the rotor at the same interval on every spin. I'm assuming this is what caused the warp and the noise. The noise went away when I drive but I know it will warp again. What could be causing this?

Parking brake cables.

Debris in the sensor ring.

Bent heat shield?

While rotors can warp, I think that the notion of them doing so is a bit over-played. IF things weren't installed correctly then it's possible. OR, if cheap parts.

Rear brakes on these cars are a sore spot. E-brakes hang. Calipers don't hold up real well. And then there's the axle stubs and bearings. Not having clean hubs will result in wheels wobbling and causing issues with the brakes.

One thing I always look for is wheels that are drier than others. Here in the PNW there's enough rain all the time to wet the wheels. Any brake that is sticking will generate more heat than the others, making that wheel drier.

Who did the brake work? What parts? Last Fall I replaced front calipers, rotors and pads on the wife's car because the existing ones, one started sticking badly, were installed by an incompetent, professional mechanic (work commissioned by PO) and were CRAP parts. A while earlier I'd found that one of the caliper slider pin holes was stripped out (incompetent mechanic at work): had to heli-coil it.

I have a grinding sound in the rear too when spinning the wheel. I changed the cables on the icy ground and put caliper release springs in. Still squeaks when reversing or on a slow take off. PO replaced rear brakes, and I am waiting until they’re gone before replacing. The dust shield appear ok. It seems to help to do hard braking and not downshift. It’s kind of fun to try wearing them down, and it helps me blend in with surrounding traffic, which often appears eager to use up the brakes!

Sounds like it could be debris/rust between the hub and rotor.
This will cause the rotor to "woble".
Also make sure that the caliper pins are free and well lubed.

Parking Brake Linkage Return Spring. For some reason, the were never installed during Assembly in Mexico. Without the return spring, the clockwise automatic caliper adjuster will tighten on the drivers side, and not on passenger side. When the drivers side caliper over tightens, the pads constantly rub the rotor causing the rotor to warp. Before I found out about the missing parking brake linkage return springs, I was replacing rear rotors every six months. Since I installed the springs, I have yet to replace the rear rotors. They currently have lasted 3 or 4 years.