Long-lived Golgafrinchans B-ark to various improbable locales, guided by Mr. Lazarus Long, here merely two centuries old. (And, yeah, I do believe that Adams was ridiculing this book to a certain extent.)
Alien cultures encountered include pleasant religious fundies, who may or may not have been duped, as well as some Borg-like rabbits, who are also fairly pleasant.
Can definitely see the libertarian politics, with all of the commentary on individual rights and property.
Crux is the possession of extraordinary longevity by the protagonist group, whom the state wishes to dispossess of their monopoly on longevity. So they go on interstellar "hegira" to avoid dispossession. Yet, even though Atlas has shrugged, the state manages another Manhattan Project during their absence to recreate the secret of longevity--so the hegira is rendered unnecessary, except for the introduction of FTL and other alien technologies into the setting.
Recommended for homo moriturus, space pirates, and people concerned with the boundaries of permissible consanguinity.