1) What vehicle ownership infringement are you talking about? All I said that if I have two parking spots and own one car, I should be allowed to rent out half of the duplex to someone who also has just one car, and without having to build two additional parking spots in order to specify an arbitrary law. I would understand not being allowed to rent to someone with 3 cars if I only have one free parking spot, as that would infringe to some extent on my neighbors.
2) I absolutely don't want to take property rights from people whose properties are grandfathered in. I want more property rights for everyone, not fewer. And I don't know why you thought I was suggesting evictions. I'm suggesting that unless there is a safety issue, then new properties should have similar rights as well.