I have one I bought off amazon. Ram mount. I didn’t like it to much. It attaches to the chassis seat mount. I’ll sell it if you want it.
Ram Mount Long Double Socket Arm for 1-Inch Ball Bases https://www.amazon.com/dp/B000WJA5ZY/ref=cm_sw_r_cp_api_i_K6LgDb6V6BF8S
I also have the ball joint that attaches the camera