While there's no indication Tesla is actually working on such a system, The Drive recently learned that Ferrari has designed a system using thrusters to enhance performance of a road vehicle (both cars and motorcycles), and has filed a patent for the system.
A search of the United States Patent and Trademarks Office reveals that Ferrari has at least two patents for the thruster system, both of them filed on Dec. 23, 2019.
In its patents, Ferrari refers to the thrusters as “pushers,” and describes two types. One uses compressed air stored in a tank on board the vehicle, while another uses small pulse jets powered by the same fuel powering the car's regular engine. The idea is that the pulse jets would be used when there's insufficient compressed air, which incidentally needs to be stored at 10,000-13,000 psi, according to the patents. The patents describe using recovered brake energy or an external source to top up the air tank.
Design of gas thrusters in Ferrari patent
Included diagrams show the thrusters mounted at the front and rear of the vehicle, as well as on its roof and underbody, and on each side. The patents mention the thrusters can be used to aid acceleration, but also help stabilize a vehicle in an emergency situation, for instance in an uncontrolled slide or spin. They can also help slow down the vehicle if used at the front, according to the patents.
Another possibility is using the thrusters to aid handling at the track. The thruster on the roof will push the vehicle to the road surface, boosting grip. Similarly, the thruster below the vehicle could be positioned to create a ground effect, and thus also boost downforce.
In Ferrari's patents, each thruster is actually made up of five nozzles of various size. Such a design means a consistent pressure can be delivered as the compressed air starts to be used up and the pressure inside the tank decreases. The small nozzle is used when the tank is full and progressively larger nozzles are used as the air starts to deplete.
While patents are certainly no indication of production intent, it's interesting Ferrari engineers have investigated the idea of using thrusters to enhance performance and appear to have designed a system that sounds a lot more plausible than strapping rockets to a car.