Auto Insurance: Liability V Collision V Gap V Total Loss V Forced Repair

My question involves insurance law for the state of North Carolina. North Carolina has a Diminished Value law. It does state that I can collect from my insurance if hit by an uninsured motorist. My question is regarding an underinsured motorist. Before the hit and run wreck on 3/12, I had a very new 2015 Honda Pilot valued at 30,000 for a trade-in. The hit and run driver was arrested and found to have liability insurance. The liability insurer found my Pilot to be a total loss. They explained that the driver only had 25,000 and that I needed to let my insurance company know about it. I did and this is where things go bad. My insurance completes an estimate on the Pilot and said it is not totaled and that they would fix it. The initial estimate using used and non-oem parts is 14,500. That is before a tear down and look inside. I fought them on using non-oem parts because they would not be covered by my Honda warranty and the Extended warranty I had already purchased when buying the Pilot. They agreed on using all OEM parts and plan to send the shop a check for 14,500 and then they expect a supplemental to outline additional repair costs. The shop has already told me the real repair is probably between 20,000 and 22,000 using oem and with other damage they expect to find. The Diminished Value of the Pilot is at least 10,000. I hired an appraisal company and they will complete a full post repair analysis, but first look is at least 10,000. I know this is right because my dealer where I have purchased a new Pilot just about every year flat told me that instead of 30,000 pre-wreck trade-in, I will now only get 20,000 even after a full OEM repair. They said normally they would not take such a trade at all. If the driver had no insurance, I could collect the 10,000 from my insurance. My insurance is saying that since the driver has liability, I have to make the diminished value claim there. Since the repair may be 22,000 and there is only 25,000 to get, I will loose up to 8,000 if the Pilot is fixed. Suing the hit and run driver will be useless. Is there anything I can do to not loose 8,000? Note: My own insurance company seems to be working against me and is fighting hard to get the Pilot fixed and not totaled. This is even after I explained that there is a salvage bid for 7,000 for the Pilot. I have asked them to accept the total loss determination from the other driver's liability insurance, collect the 25,000, and then sell the Pilot for 7,000. I would be happy if only given 31,000 for the total loss. They would have 32,000 to work with and have no loss. I am surprised and stumped that they are fighting so hard. Note: I also have Gap insurance that will pay off the 31,000 loan if there is a deficiency in a total loss situation. Sadly that policy clearly states that MY insurance must deem the vehicle a total loss. So, I am a good driver, have collision insurance, have gap insurance, and still may lose 8,000.

Auto Insurance: Liability V Collision V Gap V Total Loss V Forced Repair