Actually, Jan, on a Cloud the brakes WILL have power assistance as the power comes from the PTO disc (the servo) on the tail of the transmission. So, if the propeller shaft is still attached and the rear wheels are turning, the servo is spinning and there is power.
If it is a flatbed, DO NOT allow the rear axle to be chained or strapped down. There is a brake line that travels along top of the rear axle housing that can be crushed if a restraint is wrapped around it.
The only proper way to secure any PMC to a flatbed is with wheel baskets (or straps) secured over the wheel and then to the flatbeds mount points. There are no viable hard points on the car for chaims and severe damage can ensue.
If the car cannot get onto the flatbed under its own power, be very wary of where you attach the pull cable! you can rip something out of the car with too much tension.
If i had my druthers, for a short trip, i would use one of those tow trucks that lifts from under the front wheels. For longer trips, as Jan rightly says, i would diconnect the propeller shaft from the rear end. The truck will do all of the braking.