Just FYI - Here are the specs on the Audi 5-cyl engines vs the Waterboxer
(1998 used):

AUDI                               AUDI                             VW
Engine Specifications            2.2L I5                            2.3L
I5                          Wasserboxer 2.1L

   Horsepower                            162
130                             95
   Torque (lb-ft)
177                                140                            117
   Displacement (cc)                    2226
2309                           2109
   Turbo/Supercharger                Turbo
No                               No
   Bore X Stroke (in.)                  3.19 X 3.4
3.25 X 3.4                    3.7x2.99
   Compression Ratio                 7.8:1
10:1                            9:1