Wirelessly posted (BlackBerry8703e/4.1.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/104)
Never been there, but according to the Amtrak timetable, the Staples Mill Road station (RVR) offers "on call" rental car service, meaning that there is at least one company with a direct-line telephone in the station. Hertz, Avis, and Enterprise all seem to have locations within a few miles, so pickup should not be a problem.
Not sure about the proximity of car-rental companies to the other Richmond station, Main Street (RVM).