What?
YOU don't report the value of a car to an insurance company.
They report the value to you.
If it worked that way, all of us could run around and say our cars are worth 10x what they really are.
Unless your insurance company is really telling you to do that.....in which case, you have a piss-poor insurance company.
Their whole job is to know the value of your vehicle, and insure the value in case of damage or loss. How would they do that, if they don't know the value?