In Switzerland, you can have a licence plate for your motorcycle only with proof of insurance. (Licence plate delivered only with proof from your insurance company) So they came up with a great arrangement: as you can only ride one bike at the time, you can have two motorcycle and the bigger one covers the smaller one. I lived in Geneva for a few years so I had a 250cc scooter and the GW1500. Just one licence plate with a clip-on system... So when just riding to work, cliped the plate to the scooter, and when going for nice long rides, on to the GW. Saving some money too.

Car enthusiast could do the same (max two cars).