In addition to cars, I would like to see other transportation vehicles such as: vespas and motorcycles, scooters and skateboards for child sims, and limo rentals for prom events (HYS). I would also like to see transport related interactive shells such as: airport, subway station, bus terminal, and harbor/port. Sims would be able to purchase tickets/passes, book a vacation, and use the travel menu. This would give more story telling options for players and provide an alternative to using the phone UI.
I would also like to see transport related careers such as delivery driver. This would be a freelance career. Sims could accept gigs to make deliveries (it would require crafting an item, dish, or drink) and then using a delivery vehicle to travel to a designated location in the world, knock on the NPC's door, and hand over the item. I also like the idea of a taxi driver career. Sims could accept gigs to pick up NPC clients and drop them off at their destination. Vehicles could include: taxi, rickshaw, tuk tuk, and various model cars, trucks, and SUVs.
For a system like this to work, EA would need to make sims more open world with fewer loading screens.