You've seen most cars, BMW, Audi, Mercedes have their DSC, VSC systems where, during over-steering or fishtailing, the outside wheels would brake via computer controls, yaw control.. And for understeering, the inside would brake to make the car lean into the turn. Some higher end system cut throttle, spark, fuel etc.
This is an old idea but could be relevant today due to manufacturers having more data and experience. The next step would be to move the wheel hub (front or rear) just like the rudder system. The system is really designed to let the driver push the car until the system can kick in to keep it from fishtailing, it's better than having a set trackwidth not to mention the aero benefits. It's a balance between giving up a bit of trackwidth in the beginning in exchange for control later on. Excuse my crude sketch:
They are many ways to make the hub movement you want but I've show the simplest one. The driver or computer aided mechanism, would move inside wheel in and outside wheel out if left side steps out (taking right turn and backend steps out). The system would counteract the fishtail. Also helps car from rolling, consider it an additional roll/sway bar.
Oversteer and Understeer.
It’s the same effect as 4ws (4-wheel steering), back tires turn toward right and car serves back to the right but just another way to go about it. Can also do it on the front for understeering situation but probably not needed but you create positive scrub which will induce understeer or scrub the front tires. You can call it Track Reduction System (TRS) or a combination of both to balance the car's yaw and roll.
The effective slip angle shouldn't change but this is something that needs to be looked at.
Turning to aerodynamics, it's probably better to put the wheel position more inside to reduce the overall drag of the car during a straightline to control the tire turbulence, that is, in conjunction with the end winglets of the front and rear wing. You can get really strange with it, by moving the rear tires out, you could blow air going to the diffuser or the opposite, destroy the vacuum under the car to get some straightline speed (anti propoising), and then engage when you need the downforce or braking power.
But if you're allowed to adjust the wheel hub, why not take advantage of the in and out movement instead of just a fixed track width.
