You also have to take into consideration the age of the vehicle. In one case, I had a woman make the argument for a 15 year old vehicle. If that vehicle goes on the market today, it gets sold as used. That vehicle had 170K miles. At that point, we owe only to put a recycled fender or whatever with fewer miles. Luxury vehicles such as yours tend to have a lower number of aftermarket and recycled parts.

Then there are regulations in place. Every state I operate in allows the use of non-OEM parts, as long as it is disclosed in some fashion either verbally or via the estimate, we do both. Here, you can take a look for yourself.

This one is my favorite, nice table.

https://www.cga.ct.gov/2009/rpt/2009-R-0398.htm

Here's another website.

http://takingthehill.com/wp-content/uploads/disclosure.pdf

If you go through a claimant carrier, they will write to these standards.

The only way to avoid this? May insurers offer OEM extensions on their policies. Get one for your vehicle. If you have an accident, you will have to go through your own carrier, as the other insurer is under ZERO obligation to follow that policy. But they can always subrogate and demand the money back.