Cars would add a nice touch of realism. It doesn't matter that they would not be wholly functional - they way they worked in Sims 2 was fine, given the lack of open world.
But, in the process, I would also hope to see a total overhaul of the loading screens we get while our sims are travelling - even if it was just a still of the destination, or something, it would be better than staring for the umpteenth time at that deadly dull spinning plumbob (I have actually grown to detest it so much that I have taken to closing my eyes while it is showing). Honestly, even the loading screens we had in Sims 1 were better than what we have now!!
