Not a recommended method due to overhang, but it could be made to work

NZ method of transport. Can take 2 tandems.

Comments:-

Officially, you are allowed 30cm overhang, i.e. 30cm more than the width of the car, on either side of the vehicle.

I think would be illegal in UK as it appears to exceed the width of the vehicle. As a minimum the tandem should have forward facing white lights and rearwards facing red lights on its extremities.

Given how busy UK is I would always remove the wheels to contain the width.

Not recommended for Cornish or Pembrokeshire Coastal roads that are single track with inadequate passing spaces!