Vaguely similar in premise to Red Thunder, The Getaway Special is about a scientist who invents a very cheap hyperdrive, and the consequences of his invention.
Unlike our hero’s predictions, the revelation of the hyperdrive leads to instant mayhem as the powers of the world are brought to the brink of war. The fragile balance of power from before is shattered. The US government persecutes the inventor and the commander of the space shuttle on which the experiment was performed, forcing them to go underground. This is followed by a Heinlein-esque jaunt around the galaxy and discovery of new beings.
While not perfect, I found that The Getaway Special embodies a Golden Age optimism about our future which kept bringing a smile to my face. Sure, it is cliché that the inventor and the shuttle pilot (yes, she’s female) become lovers. Sure, it is cliché that they make a spaceship out of readily available materials (a septic tank among other things). But this does not detract from the fun of the story.