Just swap everything into another shell.

 

^this. Buy the car back from the insurance (if you have full coverage). Keep all the stuff you want. Duh. Even Jesus knows that.

Or post on the internet. Without reading your insurance policy AT ALL.

 

Appraisers take mods into account but since they don't really add value they don't affect your adjustment.

Depending on your coverage you can buy back the car and sell it for parts or swap into a shell or another complete car (what I did). Otherwise you'll just have to take what the insurance company gives you.

 

If you can produce receipts, which are less than 45 days old, the ins. Co. Will recognize them.
If the receipts are less than 6 months old, they will be prorated.
Otherwise, the ins. Co goes by the VIN.

 

I supplied receipts for mods of my 1996 GS-R and I got something like $5k for it.