It is generally possible to drive someone else's car with their car insurance, but there are some limitations and variables to consider. If you have been given explicit permission by the car's owner to drive their vehicle, then their insurance policy will typically cover you while you are driving their car. However, it's important to note that the insurance coverage follows the car, not the driver, so if you are involved in an accident while driving someone else's car, the car's owner's insurance policy will be the primary coverage.
However, if you are not listed as a driver on the car's insurance policy, you may not be covered in the event of an accident. In some cases, the car's owner's insurance policy may not cover you at all if you are not explicitly listed as a driver. Additionally, if you are involved in an accident while driving someone else's car, your own insurance policy may not cover you, as the coverage follows the car and not the driver. It's always a good idea to check with the car's owner and their insurance provider to confirm that you are covered before driving their car.