I would love to see a friction electric motor option (could work on most bikes) available to mount below the swig arm behind the center stand. Just hit a button and the motor turns a small rubber wheel that makes contact with the center of the rear tire!
I use reverse maybe once a year on my 1500 trike, they are so easy to push backwards since you expell NO enrgy holding it up.
On a sidecar rig, if really desired that much, I would think a electric assist rigged to the free wheeling side car rim would be the way to go. You'ld need tro both turn the motor on and off, observe direction, and have a means to disconnect or free wheel the drive going forward.
I'ld think better to add a grab bar to the rear frame to harness a "person" to would be easier?
Guys, Thanx for the input! Unionjk, never thought of the bikes wheel. Interesting hmmmmm.....CP...That's what I was thinking. or maybe a small gear attached to the wheel that is engaged by the starter motor on the sidecar...