Even if you SORN your car, you still need to insure it (laid up cover). A SORN car is still at risk of being stolen, and there’s a legal requirement to have insurance against the risk of it causing injury or damage to third parties or their property - e.g.
- potential injury claim if someone with impaired eyesight happens to walk into a SORN car while it’s parked up
- potential property damage claim if a SORN car is parked up on a slope, the parking brake fails and the car rolls into another person’s property
There's no legal requirement in the UK to have insurance for third parties entering your property.
If the postman trips over something on my path and decides to take me to court, sure, insurance is a good idea, but its not a legal requirement.
As for my SORN car causing damage... again, not a legal requirement.
If it rolled onto the road, I'd be legally liable but not in trouble for not having it insured for the road.
Stolen? My loss, again no legal requirement to be reinbersed for the value.
Stolen and used as a car bomb to kill 27 kids, 4 nuns and 6 (cute) kittens? No, my insurance doesn't cover drivers not listed on the policy, its their fault, not mine.