When is a car considered too old to have collision insurance?

It is not the age of the car, but the value of the car that should determine whether or not you choose to have collision insurance on it. For example, if you own an 88 Pontiac Bonneville and it's worth $500 then it doesn't really make much sense to pay $500 per year to insure it. However if you get into an accident that is your fault and you don't have collision insurance, then no one is paying for the damages to your car. This is your choice.