If either your waterpump or thermostat is leaking it is advisable to replace both to avoid another problem. On my VW dealership the waterpump/thermostat replacement cost $1200 parts and laborCan a leaking thermostat be repaired ? It looks like mine is leaking too. How much is a thermostat going for in the US (without the water pump) ?
My buddy is a tech at a Euro Specialty shop in my area and one of the regulars they see monthly has a 2016 Jetta 1.8TSI that he bought new. He uses it for Uber and, I’m not joking, just ticked over 200,000 Miles. He is religious about oil changes and I believe has done plugs a few times but otherwise it’s bone stock, auto, and has had ZERO issues. Never had a carbon clean, and has done no unplanned repairs or maintenance. VAG has had a lot of time to perfect the 1.8/2.0 based direct Injection motors and I feel they have finally produced a very reliable and mostly trouble free platform. God knows how utterly terrible the early Audi and VW 2.0Ts were, with several potential major issues, carbon buildup, oil consumption, camshaft issues, etc...I don’t worry one bit about pushing my car hard every day.