Determining your car's worth is somewhat like an insurance company calculating a vehicle's actual cash value (ACV) after a total loss. To valuate your vehicle you need to determine what amount you could get if you were to trade in or sell your vehicle at this point in time.
You can use valuation tools such as NADA, Edmunds or Kelley Blue Book. These guides will give you trade in values, retail values and private party values typically. To get the most accurate idea of what your vehicle is worth put in what options your car has, the mileage and basic condition.
Beyond these valuation guides you can look at how much a vehicle in your condition and mileage is selling for in the local car market. Sites such as Autotrader might help you in this task. Once you have determined the value of your vehicle you have the personal decision of if you want to carry comprehensive and collision coverage on the vehicle.
Once you have determined what insurance coverage you want on your vehicle, you can get a free car insurance quote.