Austin, TX Metrorail station RV parking

We are planning to attend FanFest and the Formula 1 racing in Austin next weekend (Friday). The plan is to park our 24ft Winnebago View at a Metrorail station, take train downtown, and then take the shuttle to the race track.

Does anyone have suggestions on which Metrorail station would be best to park the RV (allowed, enough spaces, easy access, etc)?

Thanks for your help.