I'm hardly alone in this. This year my government already proposed including size in road taxes: https://archive.is/HGoSB (NL, use your favourite translation service)
The CAFE footprint rule killed compact cars because huge cars were permitted to be exempt. I don't see why we'd need another such exemption, other than the business vehicle exemptions we already have (otherwise vans and trucks would be impossible to afford for anyone).
As for a punitive tax on minivans: if those minivans take up more space on the road/parking spaces/public spaces, I don't see why not. The impact doesn't need to be high enough to kill minivans in general, just enough not to drive an 80% minivan to work every day.
The CAFE footprint rule killed compact cars because huge cars were permitted to be exempt. I don't see why we'd need another such exemption, other than the business vehicle exemptions we already have (otherwise vans and trucks would be impossible to afford for anyone).
As for a punitive tax on minivans: if those minivans take up more space on the road/parking spaces/public spaces, I don't see why not. The impact doesn't need to be high enough to kill minivans in general, just enough not to drive an 80% minivan to work every day.