If I really want to experience the cruise segment between St Goar and Bingen (known to be the best, is it wise to do this (I have a car and will be driving to Marburg after the cruise):
Bonn to St Goar (1H20) by own car
St Goar to Bingen (how long is the cruise?)
Bingen to St Goar (what public transportation?) to pick up car
St Goar to Marburg by own car (2H)
Thank you !