You would want to verify that any vehicle you drive is insured. The owner of that vehicle is required to insure it. Your SR22 policy would be secondary to that insurance. You could still get in trouble for driving that car if there is no insurance on it.

If you borrow a car from a friend and get into an accident in that car, your friend's insurance would kick in first. But if, for example, the accident was your fault and the damage to the other driver's property exceeded the liability limits on your friend's policy, your SR22 insurance policy would cover the excess (up to policy limits).

You can check out different auto insurance rate quotes here.