Why not have something reasonable, and pay just the sum for given part of the year? So if vehicle spent 120 days at X, pay (120/365)xSUM, and the other place pays the rest (or X
Y places).
Thats primary school level of math that in 2026 would be trivial yo implement, if fairness is the goal. We have such thing in Switzerland, you dont pay flat yearly fees/taxes/insurances if you register your car in december for example
I don't think that's trivial to implement at all, and it leaves much more room for people to be dishonest about it, without a good way for them to check.
Re: the pro-rate for a December registration, in California at least, registrations are renewed on the date you first registered, not based on the calendar year, so there's no need for a pro-ration.
Thats primary school level of math that in 2026 would be trivial yo implement, if fairness is the goal. We have such thing in Switzerland, you dont pay flat yearly fees/taxes/insurances if you register your car in december for example