Just bought and built my Hollywood RV Rider.  I will only be carrying a Rad Mini 4, on my Ford Ranger (toad) behind my RV.  It appears pretty well built & strong.  Fully installed, no wobble.  Have not test driven yet.

As mentioned previously, bike still, no brakes during power on.  Pretty sure error 25 was what I had right out of the box on my Mini4.  Rad troubleshooting: some brake handles stick, there is a magnet inside that sticks and disables motor/bike.  Disconnect separately each brake connection near handle and then power up to see if that was the issue.  Can still ride disconnected but will not disable motor.  If brake handle is issue, try to squeeze/apply brake, release sharply, tends to unstick magnet.