A coworker has a towing business with his son in NH. He always has several Maine registered cars in his impound lot with expired or cancelled insurance that he can't get rid of because the deadbeat owners won't pay the tow, release the title, or even just haul the cars away. They're usually low end junks with too much damage to fix, either accident or breakdown related. He's required by NH law to keep the cars in a secure facility until he goes thru the abandoned vehicle process which consumes more time & money than junk value of the vehicles.
Not picking on Mainiacs, just saying mandatory insurance is a joke as far as enforcement is concerned. MikeD74T
Yep, that's my take on it too. I know it sounds like a police state to do it, but I'll bet if they started roadblock checks for expired insurance they would nail more people. Hard to verify the insurance is actually in effect. The law in Maine requires the insurance company to inform the state any time a policy is cancelled, then the state sends you a letter which you must respond to with proof of insurance. Happened to us when we changed carriers. So, like always, it's just added paperwork for honest people and the others probably ignore it all.
They don't mind pulling over 100 cars leaving the annual pot - er, 'hemp', festival over in Starks, ME - for 'suspected vehicle defects' - of course. And somehow, they always find probable cause to search the vehicle

They also stop every car going down Route 1 for OUI checks around New Years.
The point is, like you say, enforcement of insurance is a joke.
Dave.