I've seen larger AP mounts permanently mounted in trailers such as this that have survived well:  https://www.cloudynights.com/gallery/image/30771-coulter-1425f-5-newtonian-reflector-telescope-mobile/
As others have mentioned I would be more worried about emergency braking issues and the screws tearing out unless you use grade screws/bolts and drive them into the vehicle frame members.  I would suggest mounting the FSA onto a piece of sturdy plywood so you can slide it in and out a bit easier, and then use either the back seats as the emergency stop aka "headache rack" or the SUV's tie down points, or both.
Keep safe.
C