I waited at a petrol station (Shell) that my first driver dropped me off for only 10 minutes. Cars weren't going really fast as it was on the B30 and several did seem to slow down to read my sign. I didn't notice it but there was a car that did drive into the gas station premises and honked at me to get in. They were a couple/parents who recently drove from Druisberg to Ravensburg to drop off their daughter for university (starting her first semester). They stayed overnight and told me the whole journey took 7 hours. They were driving their way back to Druisberg. We didn't talk much during the journey. They dropped me off at a petrol station just outside of the city centre of Ulm, and also the spot I would need to use to hitch to Munich!