Hopefully Tesla gets video mirrors approved for the Model X; and if they are, I am sure the model S will get them, too. So, on new cars they are not allowed - yet. I have to put my stock optical mirrors back on for safety inspections. But I have had them for about 5 years now, and they are fine the rest of the time.
Here are my video mirrors:
Notice I have a small optical mirror - this is for when I am getting out of the car when parked on the street, and because habits are hard to break. Having both monitors in one place means I see over 180° in one glance. At dusk and in the rain, video mirrors are great. At night you see lights, but the resolution is lower. In bright sun, they are less useful, because of limitation in the cameras and the monitors. A shround would be a good thing.
I do not get blinded by high beams behind me. I see the rear bumpers of vehicles that are even with my shoulders - so virtually no blind spots. I see large vehicles behind me in both monitors; though a rear view optical mirror is still better for this.
The downside to the super wide angle view is that cars look much farther away that they are. You can learn how to just this by turning your head to see the car once you know it is there from the video mirrors.
As far as testing things, we are leasing our Leaf S, so I don't think my spouse will let me test stuff more complicated than the smooth wheel covers. Since we have use of regen, it is very unlikely to be an issue for cooling brakes. And I have no issues with the brakes on my Scion - cool brakes are the pride of a practiced ecodriver!
Another point that needs to be made is when the aero drag is lower, the coasting is better. When the coasting is better, you accelerate less. The energy consumption is lowered, and you accelerate less. Coasting is taking full advantage of road candy
Cd is the key thing - the shape of the car is what matters most. The bluff back of the Leaf is the biggest challenge to lower drag. Tapering the top - and sides down and inward is how to gain the most improvements. So, having the back longer would help, and the practicality of the inside volume could remain as it is.
Once the Cd comes down, reductions in frontal area have less and less affect. In Car&Driver's recent wind tunnel testing of five cars
, including the Leaf, they showed that Cd trumps frontal area: the Model S ties the Prius for CdA.
The Model S' Cd of 0.24 equalizes it's much larger frontal area, making it the same aerodynamic drag as the Prius.