All of that depends. Longevity with the company helps. Having an agent that has your back and will fight for you also helps. With an accident of this magnitude, I feel the OP has every right to fight for OEM. Especially since he's taking a huge hit on value and will have trouble reselling it. It's not like it was a door handle and he's demanding OEM for some small repair cost. The key is persistence. A lot of insurance companies obviously low ball their customers and most customers don't really know how it works so they just agree. However, the ones that put up a fight are the ones the adjusters are not big fans of. They want that claim closed and paid so they can get the next one done as well. Some of the time, you put up a fight, they will agree to OEM just so they can get the claim over and done with. I've seen some things paid out with claims that have boggled my mind and those things were paid out because our customer was persistent, a pain in the *** and we went to bat for them.

The body shop plays a role in this whole thing as well. If they are willing to take a hit on the cost and write off the difference between after market and OEM that helps as well. With the amount of damage the OP had with this accident, the body shop is going to obviously make a profit.

 

A good example is something I just went through two days ago. I needed my windshield replaced. The glass company ordered the wrong windshield. They had to reorder a new one and reschedule my apt. All that was available was an OEM windshield. $700. The glass company already screwed it up so they installed the OEM windshield and waived my $100 deductible. Obviously me sending them a ton of business helped. Allstate approved the OEM windshield without a fight.

 

Really? Well then, it's not really insurance, if they don't even *try* to bring the car back to original condition. Wow.