As others already stated for years we don't need open world to enjoy cars. There was nothing special about ts3 cars unless you just enjoy watching a car drive down streets for long periods. It's okay to watch but it's not special or immersive IMO.
I still think we are eventually getting cars and I'm excited for it. There are so many instances where cars can fit into my sims lives.
The BEST experience I ever had with cars in a video game was the way they handled driving in final fantasy XV. I never had so much fun with a car in a game. It was very immersive and interactive and I could see the sims implementing something similar. And even when you choose not to drive in final fantasy it's fun listening to the radio, watching the animations and characters interact with eachother until you reach the destination.
If not in ts4 then ts5 could do something like that.
