Correct me if I'm wrong, but isn't downforce an aerodynamic issue? There are no aerodynamics at 0 mph. You do have a torque problem, but the Tesla is actually a fairly heavy car, is it not? Also, isn't Tesla's center of mass pretty near the same height as the axles? So it's not like the rear end is going to get under the front end.
Sorry, i just worded it badly. The point is that without downforce, you can't overcome the traction issue. To a first approximation at 1g accel from a standing start, your resulting force vector is at 45 degrees (mass at 1g down, accel at 1g forward). Accelerating harder just makes the problem worse. At speed, the answer to this is downforce (e.g. how F1 cars can corner as fast as they can).
But for the first couple of seconds, you can't generate much downforce from aerodynamics because you aren't going fast enough. And there are limits to what a spoiler, etc. can generate. For a lot of street legal sports cars, this all evens out about the same way, and they end up with very similar 0-60 times.
If you try and systematically knock down all of these problems, you'll end up with a top fuel car. In that case you may get ~1000lb of downforce from exhaust alone, which gets you past the first bit while you are going too slow for the big wing to be really effective.