Cenla is still around, but last I checked they are looking for a new place to run. Participation is down and that is also hampering things. I know DELTA in NOLA still does events. You may want to check under them.
I believe you're thinking of the Drip/Grip events over at Thunder Road Raceway Park in Gillam. It is put on by 318racing.org, and it is separate from Red River Region SCCA. Autocross in Shreveport is held in the Coleman Street Parking lot just south of Bossier High School. We get anywhere from 40-60 participants per event. IIRC the next event will be in late March.