I don't know if it's still possible, but for a long time you were able to buy a month to month policy.
Naturally all one had to do was buy a policy, then get the car licensed and inspected, then let it lapse for another year.
Here in Florida the insurance industry is in on it. If you get late with your payments on the insurance policy, at some point your will get the "standard notice" informing you that the insurance company is required by law to report the status of your liability insurance to the Dept. of Motor Vehicles.
This means that if a cop gets behind you and routinely runs a check on your tag (cops and ex-cops will tell you that this is done often, especially if business is slow...and even more so if you're getting bored) the first thing that comes back on the police radio is the fact that your insurance is canceled. You don't have to have a burned out taillight, etc. for probable cause for him to stop you. He can stop you on the insurance violation alone.
It's pretty well known that your days are numbered when your insurance gets canceled.
I get tired of that excuse, "It's just an old used car and the insurance costs more than it's worth".
Duh...liability isn't for your car, it's for what damage you might do to the other guy and his car.
A $100 car can do thousands of dollars damage. That's why you need the insurance. You're putting a bet on the table that you won't crash into any of us. You crash, you lose the bet.....at least, with the insurance, we know you can cover your bet.
I found an ad in the Del Rio phone book for an agency that offers "Affordable monthly rates".
State Farm bills me biannually.