Made it as simple as possible. Did take some more thinking and planning, as it is so easy to make complicated solutions. Needed are: tent , Thule WingBar or Aerobar roofrack, plywood base 2150x1250mm, 2.6m telescopic ladder and Car Rooftop Tent DIY Fasteners. One weekend is enough for the project.

H

Purchased new U-lock for newly rebuilt electric bicycle.  OnGuard 8000 Brute LS weights 1.9kg. As they explained in shop, for so heavy lock they have no bracket. Forum discussions reveal, that plastic bracket breaks within couple of weeks.