Gradual coolant loss/usage makes me think that my 2015 GTi needs a new waterpump kit. They're pretty notorius for the thermostat housing leaking, so much so they were all recalled in the US and VW got sued for being a bit sh!t.
I've contacted the stealer, as I think the car is still within the extended warranty until Oct. Not a terrific response, no-one available to deal with this right now we'll call you back. I can't log into the my VW Finance account as, random error, despite me entering the correct detais, but am pretty sure the warranty is in place still.
Anyway. If VW won't replace their own shoddy part. I'll just replace it with a quality aftermarket kit which will give me the chance to get the inlet manifold off to check for the dreaded direct injection carbon build up issue. Car is knocking on 60k so likely is more gummed up than Lord John Gummer.
https://youtu.be/CB5ThYfX7ag?t=106