I wonder if there is a significant difference in the drivers who choose Car2Go. The first time I saw a Car2Go vehicle was in Portland, when I had to react because the driver did something foolish. I remember doing a double take to see if someone was training a new driver, and being surprised to see the carshare logo and a middle-aged driver behind the wheel. I figured it was a one-off... until a week later when I had a similar experience with a different Car2Go vehicle... and then a couple weeks later with a third.
I can't recall ever having an issue with other car share drivers, but I pay extra attention whenever I spot a Car2Go and make sure to give them a wide berth.