I have personally been through this. Late last year, I had a pristine '05 Mustang GT with less than 40k miles get rear ended. Took about eight months the get everything handled. I got made whole but there were some extenuating circumstances and, in general, it wasn't a slam dunk. Your case may be easier, since your car is nearly new, but in general, the insurance adjusters aren't very competent when it comes to this and there is no standard way to get this done as there is with other claim elements. If your dealer estimates are signed and they will attest to the diminished value difference, you may be in luck. If not then that and KBB will probably do no good. My experience is that dealers will not sign due to liability. You may need to hire an independent appraiser to get this done. Look up some on the 'net. I hired one after some extensive research but I was not impressed -- so I can't help you there. Don't use the insurer's appraiser, since they will be motivated to lowball the value loss. Not all DV claims are the same anyway. If there was structural damage, that's important. That is, if a unibody panel of any kind needed repaired or replaced, then the CarFax or AutoCheck report will be especially damaging. Be sure that is well documented. One side benefit of the appraisal is that a good one will give you their take on the quality of the repairs as well. Again, any structural stuff should be done right and all measurements done and documented by the repair shop. Note to others in this situation: DO NOT use the insurer's recommended body shop! Good luck.