Need to know of car rental agency's in Nurnberg.
All the big ones are in (now you either spell it) Nürnberg (or Nuremberg; "ü" is not the same letter as "u"). Try Sixt.com, Avis, Europcar, Hertz, Budget. If you can avoid picking up at the train station or airport as this incurs an additional handling fee of 19%. They all have got some downtown offices somewhere...
Check with gemut.com or autoeurope.
We are renting a car through Skycars and are picking it up in Nuernberg airport because my husband will only rent an automatic and returning it 8 days later at Stuttgart. Cost is 329 euro standard package for Golf
it is picked up at Sixt.