Sig Haugdahl, well known for his "speedster" car racing in the 1930s, made a test with solid rockets coupled to one of his cars.

-We see him filling the chambers, there were no less than thirty-two of them. They could be fired one at a time, in pairs, or all at once using an electrical system.

“The racing-car viewed from the rear” (PiP=pm)

-Fitted in a cross at the rear there are 20, in the front part next to the radiator there are three on each side (arrows) and under the car three on each side as well.

-Similar tests were also made by Opel (see) in both cars and gliders.

-During WWII, the suicide flying bombs "Baka" / "Oka" used this propulsion system.