I'd love to have cars for the tinkering and upgrading aspect, but am afraid they'll be just another bat/broom teleport thing.
Cars would require a major overhaul. First, there are the fx cars and cable cars zipping around everyhwere. I have lots of screenshots of them "running over" pedestrians (that's when the bandages come in handy). For real cars to not suffer the same fate, all the fx vehicles would have to get overhauled. Sims, including pets, would need to be made aware of the new cars and the new cars of sims and pets.
Next is recognizing roads as routeable territory. Whenever I try to keep my bicycle and motorbike (recolored bicycles) driving sims on a road, they route back to the sidewalk.
I can only imagine what nightmare that is/was/would be. Cars being in the works for a year sounds about right!