I would suspect there is a simple fix for future issues such as this......... "This Vehicle is protected by Audio and Video Surveillance at all times" Printed out and clearly displayed on the dashboard. We have the right to protect our property (passively), and there is no state or federal law that can remove that right. A clear advisement that the vehicle has been so equipped should cover all bases. Now there is the fact that the dealership could request and or require removal of said equipment as a stipulation to completing the work, and therefore the owner of said vehicle would need to make a decision as to whether or not to proceed.
However, I would suspect that no dealer in their right mind would make such a request as that would open them up to additional liability, as well as public scrutiny, i.e. said owner making public that they were required to remove or disable video/audio security in order to obtain work on their vehicle.
I would tend to lean toward the OPs position, as there was no attempt to conceal the device in any way shape or form. And just as with the law, not knowing is not a defense. Just because the dealership did not inquire as to how the system operated, or whether it was an active security surveillance system does not provide them a defense. These systems are readily available to the public and their operational capacity is clearly stated in their advertising.
As for me, I do not have video surveillance in my cars, but I have done my due diligence as to their capabilities. I can tell you that if you approach my house or the front of my closest neighbors houses you are and will be under surveillance. Should someone have an altercation or attempted an illegal action in which my cameras pick up, that video footage will be turned over to the police regardless.
It also sounds as if the dealer's or FCA's lawyers have reviewed and advised them to proceed with repairs. I would assume their lawyer may not feel that there was any "intentional surveillance", and that the OP could actually have possible recourse against one or both for the actions and manner in which this issue was handled as a whole.
I just happen to be reading this:
https://reolink.com/can-neighbor-have-security-cameras-pointed-your-house/
And found the following with regards to California Law:
"There are no restrictions, for a private person to have video surveillance cameras around their property for the purposes of security."
"If your cameras are located on your property in plain view, are not in a private place, and do not violate any state or federal laws, it would appear they would be lawful.""
For the person that was quoting CA law. It is not clear that this would be for vehicles as well, but if it is not already, one legal challenge utilizing this statue I would suspect would be hard to beat. As the premiss is the same... To protect ones property...the back ground being incidental to the primary focus of protecting ones property.