But what was exigent that gave them lawful and full access to his vehicle with no warrant?
I think he was being too open and honest and logical with the cop.
Unfortunately, that's a procedural question. The police can violate your civil rights (unreasonable search/seizure first, 2A second, and I'm not sure what with family separation), and you can appeal.
That's the check written into our laws. Unfortunately, it's not frictionless. It's expensive and it takes years.
The government agents, and the spiteful wife, both know that.