Why display a valuable bike on the roof of the car like a trophy? I bet the car was otherwise empty! There is no car that can’t take a bike or two or even three (most estate cars) with the wheels taken off. We can hide two bikes in the boot of my Passat estate with the cover closed, so completely hidden from view.
I’ve even seen people driving around in vans with bikes on towball racks, FFS!
As for getting the reg of the scooter – why not make it obvious? Then make a call to your local beat officer, who will be very happy to receive intelligence on local scooter scroats. Ours has recently issued Section 59 warnings to two local scooter idiots who were annoying everybody in our street and we haven’t seen them in six months now.