I was involved in a rear end collision in my 2017 Camaro SS and it caused about $8k worth of damage. Prior to the accident my vehicle was worth about $29k (with the inflated market accounted for as well). After the accident I'm getting estimates of about $21-22k which is a significant loss.
Where are you getting those estimates from? If from a dealer they are BS.
See Page 22 of the following document for an explanation of the position of Texas courts on diminished value.
DIMINUTION OF VALUE IN ALL 50 STATES (00165375).DOC (mwl-law.com)
does this sound like the insurance company trying to get out of paying?
That's exactly what's happening. What you have to understand is that the other driver's insurance company is not your insurance company and owes you nothing until a court of law says so and says how much.
Until then they can say whatever they want and deny your claim for diminished value. If you disagree you will have to sue for it.
There is no limit on the age of the car. It should be obvious, however, that the older a car gets the less any diminished value becomes and seldom worth the cost of litigation.
In your case, don't count on getting any additional money beyond the cost of repairs just due to the stigma of the car having been in an accident. Texas case decisions don't appear to allow it.
You can look up the case decisions on Google Scholar. You can also search for diminished value and read other case decisions that address the issue.
Google Scholar
To illustrate the difficulty you face in proving diminished value, especially in Texas, here are two diametrically opposing viewpoints of two attorneys.
Attorney 1:
In my view, diminished value damages are completely speculative and improper. You don't know if you'll ever sell your vehicle. It might get totaled in another accident. It might get destroyed in a fire. If you do sell it, you don't know when you'll sell it. You also don't know if the person to whom you sell it will make an effort to research the car's accident history. You also don't know if your ultimate sale price is based on market conditions, the buyer's negotiating skill, or your desperate need for money. Accordingly, giving you something based on "diminished value" could amount to compensating you for damages you may never suffer or grossly overcompensating you.
Attorney 2:
If a car had a scratch on it because of an accident, it will have a lower value because of it and the damaged owner is clearly entitled to compensation for that damage. You might say, that scratch can be repaired, and that’s true. A car owner also gets compensation for damage done to a car that puts it beyond repair, as well. So what is the difference here: if the owner has suffered a loss in value, repairable or not, he ought to be entitled to compensation for that. Saying that the diminished value is too speculative for the reasons he gave doesn't fly because cars can be valued given their history and the loss determined with reasonable accuracy. It's done all the time. Cars with salvage titles, for example, are worth less than those without such titles even if they appear otherwise to be in the same condition, and that difference can be computed. Same with the diminished value claims here. I agree that the amount of diminished value in many cases is not much, but to the extent it does exist, it ought to be part of the compensation owed.
You are free to sue in small claims court if you like. You will need to pay an expert to testify in court and you don't get that money back.
I did see that you have a 2 year period of which you can file the claim after the accident..
It's two years to file a lawsuit, not file a claim. You can file the claim any time you want to but if you miss the deadline for filing a lawsuit, it's all over.
Bottom line: Keep your car for another 10 years and the accident history won't make much difference in what you get for it.