hey man sorry to hear about your loss. I may be too late being that this happen the middle of last month but the best thing you can do is get proof of everything you bought and put on the car. Also print out 4 sale ads for other ITR with the same mileage and year as yours to help in settling your total loss settlement. Unfortunatly depending on her or your insurance most things like bolt on exhaust and stuff like that are considered "preference" and may not add the same value its worth. (i.e r
real mugen exhaust vs a meagan exhaust both would be held to the same 'standard') With a car like an ITR you may be best just keeping the salvage and parting it out.
Hope it works out for you.
P.S I am an adjuster For geico so i deal with this kinda shit all the time