I mentioned this in another thread so I'm just going to copypaste it here too:
I'd love it if emotions were implemented with cars e.g. angry/tense sims would slam the car doors and clench their jaws when driving, playful sims would beep the horn/flash the lights etc, sad sims would rest their head on and cry at the wheel (not when driving, obviously). A brand new car would make sims happy but buying a dirty, cheap one will make them uncomfortable/tense. Cars should also come with a reliability score like appliances do. Cars with low reliability will break down more often than expensive ones with higher reliability (obviously). Breakdowns, if left long enough, lead to fires.
I'd really like them to not only focus on personal cars for sims but service vehicles for the NPCs too e.g. maid, gardener and repairman vans, school buses, fire engines, the repo van. When/if we get burglars I'd love for them to include a getaway car/van instead of them just sneaking on/off the lot like in past sims games.
I hope they make the interiors a bit more detailed than they were in past sims games (bit of an ask, I know) but I think that would be great for storytelling purposes. There are a lot of movies/tv shows where there is a interior car scene so to have this in the sims would be really cool and great for stories.
They should be very expensive to buy and run unless you buy a cheap one. I'd like to be able to wash cars and have children and teens be able to do that as well as adult sims. Cars should need re-fuelling every so often - if you have the Eco Lifestyle pack buying normal fuel (rabbithole) would harm the environment but using biofuel from the beetles won't.
I hope they update the deco cars driving around in the background too as they aren't very pretty right now.
I would also love to have a proper convertible car with roof on/off options (I don't think this has ever been a thing) and motorbikes, too! The ability to set ownership as well.
