Don't formally accept their estimate yet.

Have you gotten any estimates yourself?
I had to fight my insurance for a reasonable value on the Fiery Juke. They said if I could show them three similar cars listed for more money, they would adjust the value, and they did. (And actually got a very generous settlement.)
So go get two quotes for repair and submit them as examples to your insurance.

A guy at the Nissan dealer told me that claims department people are paid a bonus to get you to accept their initial "low-ball" offer. Then they have two more tiers of offers they can make -- the final one being actual market value.
I don't know if this applies to repairs as opposed to vehicle replacement -- or even if it's actually how it works -- but it seemed to be how it worked for my situation.