SpaceX and Tesla CEO Elon Musk announced bold plans to combine the technologies of his two biggest companies by placing rocket thrusters on future specialized models of Tesla’s Roadster. The thrusters won’t actually combust, according to Musk; instead, they will expel highly pressurized cold air.
https://www.theverge.com/2018/6/16/17459224/tesla-roadster-elon-musk-spacex-falcon-copv
* by placing rocket thrusters on future specialized models of Tesla’s Roadster * supposedly one of the fastest cars in the world * second * the COPVs would take up a good chunk of the car * that friction between the propellants in the engine tank and the COPV was to blame * specific impulse of about 70 seconds