Pretty much just a helmet, a seat belt, and car that isn't falling apart. The tech inspection is a little more involved then at Trails because techs will be checking not only battery hold downs, but will be shaking on your wheels looking for anythign loose, good tires, and making sure the springs on your throttle body will spring it closed. Nothing major, just general saftey stuff. Keep in mind that a tight autocross course will not allow much speed so specific saftey stuff isn't as much of an issue.