You should hold on to full-coverage auto insurance until your annual premium meets or exceeds the estimated payout if your car needs to be repaired or replaced. If your car is five or six years old, the payout for replacement probably isn't worth what you pay in premiums.
Why do I need full coverage?
Full coverage insurance provides coverage for most scenarios, including damage to your car from the weather, an at-fault accident, hitting an animal or vandalism. It will even pay out the current value of your car if your vehicle is stolen. Required? Medical costs due to injuries or deaths from an accident you caused.