I think your Dad's heart was in the right place - he wanted you to have a newer, more reliable vehicle, but then he probably got caught up in the expense of it, or maybe the buying excitement, and took control of the situation. I don't know where you are but cars are actually hard to get right now here in the US, especially popular ones. No discounts. Lots pretty empty, except for high priced or low-demand models. Part of the whole Covid supply chain disruption.
Undoubtedly he should have involved you though, or waited, like you wanted to do. And he should have been able to get his deposit back.. with the demand for cars they can certainly sell it. It would have been better if he offered to help out with a certain amount, and then you could make the final decision and bear the additional cost on your own. Then no hard feelings and it is what you want. Maybe he could still do that with the dealership.. and apply the deposit accordingly?
I really do like Dee's point though. If we want to make decisions that work best for us, it's best to handle these things on our own. Which is what you were trying to do all along. I'm so sorry WindPines, especially that he seems so angry about it all. Sometimes family dynamics are really difficult. They almost seem pre-destined to fail. It happened in my family too. Another reason to find a better way.