While CBS didn't renew Wacky Races for a 2nd year, it did green-light 2 spin-offs from the series, both set in earlier times.
The Perils of Penelope Pitstop was set in the roaring 20's, presumably during the silent film era, which coincidentally the series is paying homage to with the cliffhanger format. Sadly, the cliffhanger endings originally used were edited out of later reruns and the DVD release of a few years back. In a way, it seems to make a wee bit of sense, considering how Boomerang has played Perils into the ground the last couple of years with relentless daily airings.
Anyway, aside from a mention of Dick Dastardly, who now had his own series as well, there are no links between Perils and Wacky Races. Likewise, Races is not mentioned at all in Dastardly's series, suggesting that, indeed the Races took place much later chronologically. Sources say that Dastardly was supposed to be joining Penelope (Janet Waldo) and the Ant Hill Mob on this show, rebooted as a bodyguard to Penelope's heretofore unseen brother, but plans were nixed.
Penelope instead must deal with a greedy guardian, Sylvester Sneekly, aka the Hooded Claw (an uncredited Paul Lynde, Hollywood Squares & Bewitched), who wants Penelope's inheritance for himself. The series ended without a final resolution, which allows fans to create their own ideas on how to close the show properly. I'll share mine another time.
Following is the intro we all remember:
Gary Owens, who was now on Rowan & Martin's Laugh-In by this point, served as the narrator in what would be his last gig for Hanna-Barbera until Dynomutt in 1976. The rest of the voice cast consisted of Paul Winchell, Mel Blanc, & Don Messick, who divvied up the voices of the Ant Hill Mob. Blanc, of course, provided Chuggaboom's sound effects and the unified dialogue of the Bully Brothers, the Claw's twin henchmen.
Would this series work today? Maybe, depending on how today's writers could reinterpret the show for a modern audience. It'd have to be reset in more modern times, because leaving it in the silent era won't pick up new viewers.