After two weeks I have the GTD back from the dealership and all's good.
The roof leak is no more.
MK7 sunroofs are bonded to the roof, unlike the MK6 apparently; a specialist firm visited my dealer to remove and re-assembly the roof assembly.
In the interim was loaned a CC DSG, surprisingly nice, for sure. Second week was a Tiguan R-Line, not my thing to be frank, cheap leather, nice electric adjustment though, ability to take a load of crap down the skip impressed unlike its thirst.
Today I clay barred the car for a couple of hours, polished, GTechniqed (wheels too).
Plenty of fall out gathered by the bar, especially from the front wheel arches and boot spoiler.
Polished the glass, GTechinqed the seats and only now (after what seems like an age) I feel like the cars sorted.
Brought a TomTom air vent holder this morning which I'm happy with. Off to Cologne in the morning, interested to see if I can get from the Shell station in Folkestone to Ludenscheid and back in one tank like the MK6 can. Will post findings, to share.
BTW, standard GTD wheels look wicked once polished.