Last week I was visiting my son who lives in the west suburbs of Phoenix. He noticed coolant dripping on the belly pan and on some hoses. He took it to a local franchise shop and they did a coolant pressure test and verified it was the radiator. They quoted him around $2k to replace the radiator, hoses, and some other random work. Basically it was all up-sell and overcharge.
I searched a bit here is this section and found Autobahn Motorwerks. Autobahn Motorwerks is a VW/Audi specialists shop about a 25 minute trip from where my son lives, located in North Phoenix a few blocks off the 17 in an industrial park. It's sort of hidden between and behind some other buildings. They quoted him $600 for a radiator replacement, and replace any O-rings in any hose fittings they have to remove.
As my son's car is 10 years old I suggested a timing belt and water pump replacement service while the car was there. That AZ heat is hard on rubber. The whole job was done for around $2K. A very reasonable price for that amount of work. Autobahn Motorwerks only uses VW or VW-OEM parts from either VW or WORLDPAC. The turn around time was 2 days from drop-ff to pick-up.
Kudos to those guys. Henry the manager is a VW/Audi enthusiast and I could have spent all day just talking cars with him. Whenever my son needs any work, that's where he's going.

Autobahn Motorwerks
2001 W Cheryl Dr.
Phoenix, AZ 85021
623-435-6989