Advice Needed Insurance Wants to Total Car Dinan 4.8is

[4.8isguy]

So two weeks ago my car was hit parked. A car ran a stop sign and was t-boned into my car. My rear bumper, rear tail gate(top & bottom), tail lights, and right dinan muffler were impacted. None of the damage was serious but enough to make everything unacceptable to leave as is for my standards. So bodyshop puts together an estimate of 5600 to get the car good as new. I'm satisfied. Then insurance comes in and has him cut off the repair at 2900 otherwise they will total it due to the value of these things. Estimate is using aftermarket rear bumper, used tail lights, etc. I really don't want to total the car out. I am at zero fault here. Car that ran stop sign is 80 the car that t boned him is 20. Car is running mechanically like new. Currently sitting at 98k miles Full Dinan Stage 2, Brembo BBK all around, underride kit, European Clear headlights, Euro Fender Flares, Completely upgraded sound system with stealth sub, etc. All original paint on car. I wouldn't sell the car for less then 15k. What do you guys recommend?