einsgruber

I'm probably going to replace my battery soon; any advice on brand/type for a 1.8T B6?

Turbonater

Factory batteries are good quality and reasonably priced.

Interstate has a good reputation but I am not sure why.

Exide and Diehard are reliable brands in Canada.

For my money I would go to the dealer and buy a factory replacement battery. You get a great warranty and the batteries are good quality.

Hugh B

I concur. When I needed a new battery for my S4 Audi's price was similar.
I've even bought Castrol from them at a cheaper price than any other retailer.
Hugh