Regulate as they see fit...a tax stamp located in the windshield (think emissions sticker) would fit the bill. Licensing is used to show proof to other states' municipalities. If Missouri desired they could choose to not issue a license and switch to a tax sticker. Other states would need to recognize the tax sticker.
All of the non-revenue functions of auto registration and licenses to drive (which in mind serves as a near universal ID and as a bail card for minor traffic offenses) could be served with a very modest fee to issue a license plate which could be valid forever and a very modest fee to issue a driver license which could be valid for 10 years or until you change addresses, whichever comes first.
Issue a new DL to update the photo for $15 every 10 years, or to update the address for $10 as needed.
Charge a $5 administrative fee to update addresses on license plates.
Require proof of insurance to be carried in the car and/or submitted to the DMV every year.
If emissions and/or safety testing is required, nominal fee and a sticker that expires. But as discussed in
this article emissions compliance is achieved a lot less expensively and invasively by setting up mobile testers at the bottom of freeway off ramps than by forcing everyone to run his car through an emissions test every year. Utah just dropped our safety inspection based on data from most other Western States that don't have safety inspections and have no higher rate of equipment failure related crashes than do States with such inspections. Turns out the guy who owns/drives the car has a pretty good incentive to keep it in decent repair and the kind of problems that cause crashes can crop up between mandatory annual inspections anyway.
Short story long, most everything else about DLs and DMV is clearly just a revenue function.
Whether a car is new or old, luxury or economy, motorcycle or F-350, really has no effect on the cost of building or maintaining roads. From the lightest of cars up through the largest of standard passenger trucks, weight differences just don't matter. Heavy commercial trucks (ie tractor trailer rigs) and freeze-thaw cycles are responsible for most road damage. But luxury taxes or otherwise soaking the rich is politically painless, so most places impose higher taxes on newer and/or more expensive cars.
An odometer reading or GPS tracker is the most accurate way to gauge taxes or tolls for fair share of road usage, but are also more invasive than most of us care for. So a per gallon gas tax is a close enough approximation at least until alternative fuel cars get far more numerous.
If the revenue is to be collected, I wish they'd at least give us the option to pay it less often in larger amounts and spare us the hassle of annual registration on the cars and having to renew licenses every 5 years. I know some States have much longer terms on these items.
What is quite clear to me, however, is that State and local governments are fully within Constitutional constraints to impose these taxes and registration & licensing requirements on those who operate motor vehicles on public roads. Despite some emphatic assertions, I've never seen any actual evidence to the contrary.
Charles