Like any sanctioned event, SCCA and PCA in particular, an auto cross can be more fun than you've ever had or an endless pit full of problems and regulations, depends on your temperament.
Expect an experience similar to a trip to the DMV. They check the car, the suspension, the brakes, fluid leaks, seat belts, steering, loose items. etc. They check you for license, helmet, etc. Any modifications at all will bump you up into classes where you can't possible be competitive. You're expected to stay behind or in front of or beside or close to or far away from any number of things. After you run the course you'll be expected to monitor the other "racers" and man a station along the course, so don't plan on meeting up with anyone or doing anything to your car. A whole bunch of fat guys with badges on their sleeves will tell you what to do from beginning to end.
Anyone who's ever participated, knows what I mean. Some folks can stand it, some actually LIKE the "as safe as a Sunday drive" atmosphere. A GREAT day for veterans and mailmen, otherwise WAY too "structured" for a guy like me.
Drag racing and hill climbs are more fun, an autocross is like waiting quietly in line for recess. By the time you get out there you've had all the excitement bored out of you . . .