Report Offensive Message

It doesn't seem likely that a company that has been around for at least 5 years hasn't done its research on insurance and federal laws. It appears that you are paying Zimride for the service, which then pays the owner of the car. If this is the case then there are two scenarios:
The passenger has paid Zimride, so the passenger is just a passenger and the driver's insurance pays in the event of an accident, or
The passenger has paid Zimride, so Zimride is the responsible party in the event of an accident.