I don't know of any Florida "enduros", but I've heard of an annual event at the Ocala National Forest called Safarithon, or something like that. I believe it's held once a year in the spring time where they have timed, obstacle-course-like off-road and outdoor events.
As far as amateur participation at the SCORE races in Baja, I don't know. We've all heard of the Trophy Truck professional teams, such as the ones that made Ivan "the Ironman" Stewart, Robby Gordon, Larry Ragland, etc., famous. I've never been to a Baja race, but a buddy of mine at work once raced a motorcycle many years ago in the Baja 1000, and he was not a "pro". Plus, I understand many teams welcome any kind of volunteer "pit" help during the races. Be sure to check out the message board at www.race-dezert.com
. Lots of good racing info on that forum.
By the way, with your screen name as JAXPCS, are you by any chance from Jacksonville? I used to live in Palatka, just north of the Ocala National Forest.