In all honesty running on low box won't produce that much heat, the engine isn't really working very hard due to the gearing, 10-20 minutes of cruise at 60 would normally do it, in my experience, and yes I have had it happens a few times just not from turbos
Not from what I can find out, they are owned by TMD Friction, which has been bought by -AEQUITA - Private Equity Investors , which always means quality goes one way.
It's the same over on the Audi forum frequent, everyone gets a jaded opinion of the mark because no-one posts up when things are running OK.
Plus of course it couldn't *possibly* be down to people putting oversized tyres on them and trying to crawl slowly.
It's just a common problem with LR calipers or pads not made right.
I'd try and get something reputable and not from the usual suspects, e.g. EBC, even avoiding Lockheed.
I've had this, maybe even still do slightly have this with new, cheap, calipers on the rear, I'm more suspicious of the pads, I will try a different brand should it become worse.
I hope you're not having a third bad thing.... I've had one today, I left the locking wheel nut tool on the Audi wheel bolt and went for a drive.... Doh.
So there are two steel pipes with a bleeder that run along the passenger rocker cover/valley, bolted to inlet manifold, they often rot out, but may be available new still.
You can see them here:
Also, you can see the small aluminium bracket made to hold the MC feed lines in, otherwise you could knock them out and make a terrible mess/lose brakes. It is held in with the original Tesla roll pin.
Some people have 3D printed things to do the same job, this took me 20 mins, and about 5p worth of aluminium offcut.