Aprilia Habana Episode: 1.01
Aprilia Habana or Mojito: http://www.picautos.com/images/aprilia-mojito-50-08.jpg EDIT: Ah! Now I found out that Mojito was the American name for the Habana.
BMW R1100GS Episode: 1.01
BMW R1100GS (or the smaller R850GS)?
BMW R80GS Episode: 1.04
BMW R80 GS
Yep. Specifically, it's a R80 GS Basic.
BMW R1150 RT-P Episode: 2.01
2001 BMW R 1150 RT http://www.polizeiautos.de/show_one.php?id=2032 livery changed that period
BMW R1200RT Police Episode: 3.01
BMW R 1200 RT
Yamaha FZS600 Fazer Episode: 5.03
Yam FZS 600 Faser, 98-04
Piaggio Vespa 50 Special Episode: 5.06
Piaggio Vespa 50 (Mofa oder Moped...)