Dana Wynter pronounced her name as "Donna" not "Dayna." The narrator introducing the actors during the opening credits did indeed pronounce it correctly. (Clips of game shows like What's My Line can be found where she is guesting, and her name is pronounced as Donna.)
Wesley Sanders' (Don Dubbins) driver's license gives his birth date as 9/12/37, making him about 30 - almost a full 9 years younger than Dubbins' actual age.
Throughout the series they use the same automobiles; maroon 1967 Ford Galaxie 500, blue 1967 Ford Galaxie, green 1967 Ford Station Wagon, and blue 1967 Mercury Comet 2-door.
The fluoroscope image of Sanders' chest is the same x-ray negative seen in the just previous "Labyrinth".
Dana Wynter starred in another "the aliens are here, they look and talk like us and nobody will believe me" type feature, the film Invasion of the Body Snatchers (1956).