Insurance companies have know to drop folks to admit to custom parts.
They offer you an option to declare them but I believe that's a trap.
Once you have receipts, they pay for aftermarkets parts anyway, so makes no sense to give them a reason to drop you.
https://www.clublexus.com/forums/is-...omization.html
https://www.corvetteforum.com/forums...fied-cars.html