I know that you use Audi TT, Golf etc calipers to upgrade to 312mm brakes, But what would stop you from using calipers off another car make like Vauxhall?

In my eyes the Vaux calipers look exactly the same as the TT ones. Could it be that they are the same caliper? Or would the bolt holes be slightly different?

Difficult to say unless you compare two.

They are usually made by one of only a handfull of manufacturers but I doubt the mounting bolts holes would be in the same place, plus do VAuxhalls come with 312mm brakes?

The mk4 GSI came with 308mm. But ive been looking more and more at them and the brake line is in a different place along with a few other small differences. Ah well ill sell the vaux ones i have to fund the correct ones.

Thanks anyway Lummox