I know this is a long shot, but a full brake set from a 2010 GTI just fell into my lap, what are the chances I could fit these to my A4?

 

bump for weekend crew.

 

I've never heard of anyone using them but there are several other VAG cars whose brakes can be used. Before you try it, what are the advantages? I haven't checked out those brakes so I know nothing about them. Are they larger or of a better design?

First off, go to tirerack.com and look at wheels for that car. Check the bolt pattern on the wheels. Our cars have a 5x112 bolt pattern and if the GTI has it too then that's a good first step. It may have a 5x100 pattern though like the TT and Jetta. Beyond that, it's a matter of seeing if you can mix and match components to use them.