I found this post below from @MongooseGA from ~15 months ago WRT insurance company . The "SWIM" para below makes me smile...
Cheers mates,
G
This is, I would say, the norm. Ex: I was lucky in that a corporate vehicle hit my freshly build '00 LC last Summer (dump truck). I had literally just installed the springs the night before, and had about $20k in receipts from parts and labor in the previous 2-3 weeks. I fought them for weeks to get a check that was enough to replace "MY" truck. That's the thing... I was in a fortunate position but even still, they just wanted to replace with another $8k LC. No, no, no. "MY" truck had $20K worth of investment in it, and nothing they were going to point to as comps would have. Eventually I got to the point of calling an attorney and only then did the higher-ups step in and cut me a check that started with a '2'.
Your trick is what most people do. These totalled vehicles go to auction and get purchased by rebuilders or scrap yards. Strip the good stuff and replace it with whatever fits in the spot.
SWIM (someone who isn't me) had a totalled LC100 with a lot of money in new parts on it. That same person now owns a 2005 LX with a very similar mod list to the aforementioned LC. The LC, as I'm told, went to the scrap yard with blown speakers put back in, Tundra steelies and bald tires, blown OEM suspension, etc. If only those SS DT headers weren't such a bitch to R+R...
Cheers mates,
G