Anyplace that sells batteries can tell you the correct size. You do not have to buy the same brand that came in the car from the factory.
The 2011 Audi R8 has a 6-speed manual.
The 2014 Audi R8 has a 6-speed manual.
The 2008 Audi R8 has a 6-speed manual.
The 2009 Audi R8 has a 6-speed manual.
The 2010 Audi R8 has a 6-speed manual.
The 2012 Audi R8 has a 6-speed manual.
The 2010 Audi R8 runs on premium unleaded (required).
The 2009 Audi R8 runs on premium unleaded (required).
The 2014 Audi R8 runs on premium unleaded (required).
The 2008 Audi R8 runs on premium unleaded (required).
The 2011 Audi R8 runs on premium unleaded (required).
The 2012 Audi R8 runs on premium unleaded (required).