The only way I would even consider to have one of these things is if the insurance premium would be reduced proportionally to how much I (don't) drive. Only use the car on Sundays? Pay 1/7 of the price.
But of course prices can only go up.
But of course prices can only go up.
You pay a small retainer fee ($1.50/day) and then a per mileage fee. This requires the use of a logging device which also impacts your per-mile rate depending on your driving.
I haven't dug into the nuts and bolts of this, but I wonder how well you are covered when the vehicle is not in motion - parked in garage, on the street, etc. At least in my area parking in public can be a risky option between the hit and runs, catalytic converter theft, break-in, etc.