Autocrosses are NOT spectator events and not intended to be "thrill rides" for the general public. If you register in your car as a DRIVER at an autocross, people are generally willing to take you along as a passenger for instructional purposes.
As an event organizer for the FAST club, I'd rather not have you there just to take rides with people on a "date". That's just not what we're about, not to mention that we're not insured for it.
But, if you want to REALLY have fun, sign up as a driver!