I would say NTA. But I’m not surprised he was upset. If he participated in selling the old car with the expectation that the car you inherited was taking the place of the old car and would be mutually owned, it was because there wasn’t clear communication.
Regardless, he doesn’t get to make unilateral decisions with mutually owned property. So even if he thought the car was mutually owned, he can’t just make decisions that disregard your opinions.
Highly recommend the Bulwark Podcast Presents: The Corruption of Lindsey Graham.
It’s fascinating how he presciently described the danger of Trump for our democracy and then became a boot licker.