Insured cars

In The USA this will vary state by state according to local regulation as well as the type of Auto Insurance Policy in place at the time. But It's pretty much the same as UK. It's always best to get coverage advice from your Insurance Agent.

As a general rule, If Coverage is afforded under the vehicle owners policy then it will act as primary coverage. If coverage is not available to the driver through the owners policy then the drivers own auto liability insurance can invoke as first party coverage The drivers auto insurance policy, depending on the policy and broad coverage providing, liability, uninsured motorist and medical portions of your personal auto insurance policy can follow you and provide coverage.

Your Personal auto Policy will "Not" follow you for operation of a hired business or commercial use vehicle.

If the "personal" use vehicle being driven has adequate active coverage then that policy is customarily treated as primary and any coverage the driver has is secondary or excess in the event damages exceed the limits of the vehicle owner's insurance policy or the event of no coverage for the operator under the owners policy.

If the vehicle owner has purchased a limited form type or a "named driver" policy. though sometimes economic, no coverage at all may be afforded to occasional or permitted drivers.

The degree of coverage beyond the above that may invoke are dependent on various factors such as the reason for driving the other vehicle, loaners, rentals or replacement status vehicles and other local or state regulations.

It's always best to talk with your agent and make sure you undertsand your coverage before loaning or borrowing another vehicle.
The Top Ten Insured (Quoted) Cars in the UK
Rank Make Model
1 FORD FOCUS ZETEC 16V
2 FORD KA
3 VAUXHALL VECTRA LS 16V
4 PEUGEOT 206 LX
5 FORD FOCUS LX 16V
6 VAUXHALL CORSA SXI 16V
7 FORD MONDEO ZETEC
8 FORD FOCUS GHIA 16V
9 FIAT PUNTO ACTIVE 8V
10 NISSAN MICRA S

In the UK - the general rule is that the driver's own vehicle insurance will pay for any accidents other than when the driver is driving a car with permission and is named on the car owner's policy of insurance to drive the vehicle. If the driver has no insurance the driver has a personal liability to pay for injuries and damage to third parties, but either the car owner's insurance can be used to meet a compensation claim or the Motor Insurers Bureau will step in to pay compensation if no car insurance is available from either the driver or the owner. See the related link entitled "accident car insurance" - for an explanation of all forms of car insurance in the UK and the function of the MIB.
Insurance Coverage in Someone Else's vehicle - US
In The USA this will vary state by state according to local regulation as well as the type of Auto Insurance Policy in place at the time. But It's pretty much the same as UK. It's always best to get coverage advice from your Insurance Agent.