I had the same problem. Homeowners wouldn't cover it b/c it was a motor vehicle and car insurance wouldn't cover it either b/c there was no motor in it yet, so it technically wasn't a "motor vehicle" as far as car insurance was concerned
. I installed the motor as fast as I could and got it covered, but I was a bit nervous for the first few weeks without insurance. I had all sorts of visions of hurricanes and fires destroying my garage and the car.