This is a hypothetical question.
If I had built a custom car from scratch everything from a space frame chassis to hand crafted body panels and a high end concours quality paint job (still used often on the road). I then had a crash that wasn't my fault e.g someone doesn't look at a T-Junction and pulls out on to a main road right in front of me. My car has body damage if I claim with the insurance they want the car taken to a body shop but I want the money to carry out the repairs myself and put back to how it was with no cutting corners. Can I get my insurance company to give me the money it would take to get it back to how it was or can I sue the other driver for the costs?