you can fit different wheels than 6" and ET48....
I have 16x6.5 ET50....
On mytyres you have a choice of wheels.... there are plenty with ET50 at 6" wide.
They are fine to use on Mk7 GTD.
Alternatively I can sell you my 16" Audi speedlines with 205 55 16 tyres (2x Michelin Alpin A4, 2x Avon Ice Touring ST - all approx 7-7.5mm)