I would not use the laundry in the hotel anytime. There probably are dry cleaners with 24-hour service 10 minutes away. Pizza places deliver. You also can stop at a supermarket on the way to the hotel and get what you need, and ask housekeeping to empty the minibar. Look at rental car fleets as flocks of migrating birds.
Rental cars are really reasonable in Germany vs. Switzerland or Austria.
While I normally rent a standard-shift car because they cost far less than an automatic, I prefer an automatic in countries like Britain, since sitting on the right and shifting with your left hand takes some getting used to. Whenever possible, I use my gold credit card's car rental coverage to decline the collision damage waiver insurance options, which typically doubles the weekly rental car rates. AAA often has reciprocal agreements with auto clubs abroad. You may get free road maps just by presenting your card. When renting a car, specify a subcompact or the smallest car size of which you are aware.