Do you have to accept the cash if your car is totaled or can you tell them that you want to have your car fixed?

If you have collision insurance, they will pay out up to 40-70% of the value of the car in repair costs. Over that amount, it is considered totaled., and they cut you a check for the value of the car. The percentages vary with companies, vehicle, etc. You don't have any say in it. If you have only liability insurance, you're on your own for the repairs.