I finished a change to our CARS to FSUID bridge this morning.  
Audit students will now show as current students.  What follows is how I look them up:

select TERM, YEAR from fssas.term_info where current_date between start_date and end_date
Gets the current Term and Year

select STUDENT_ID from FSSAS.AUDIT_COURSES where YEAR = '$currentYear' and TERM = '$currentTerm' and STUDENT_ID = '$ssn'
Returns a record if the ssn provided is for a current audit student.

select LAST_NAME, FIRST_NAME, MIDDLE_INIT, SUFFIX from FSSAS.AUDIT_MASTER where STUDENT_ID = '$ssn'
Grabs the student's name

From here, assuming the student has an FSU card (the card type does not matter) they will be eligible for a CARS account and FSUID.

Please let me know if you have any questions and thanks to Doug for helping me out with this.