Sorry to hear a tree fell on your car. You are right. Your comprehensive coverage
will cover the damage to your car. As far as the car seat goes there are a few things to take into consideration. Is the car seat permanently installed in your car? If it is then you would need to have special equipment coverage to replace the car seat. Special equipment coverage will cover anything that is added on to the vehicle that is not factory installed. For instance, a wheel chair lift, or in your case a specially designed car seat. You would need to show receipts/proof for the cost of the car seat. If you do not have special equipment coverage then it is up to your insurance company as to how much they will compensate you to replace the car seat. If you have home
or renters insurance,
you can also see if they will compensate you for the car seat if the tree falling happened on your property. Good luck and don't hesitate to ask
if you have any additional questions.