Chevy commercial

Astronauts and Corvettes were pretty solidly linked for several years. Shepard drove one when he joined the Mercury program, and GM gave him a free one after his first space flight. They would have given the other six free cars, but NASA rules forbade accepting free gifts or making endorsements, so they were offered $1 annual leases on two cars each. Six of the Mercury astronauts leased Corvettes for themselves, and the wives got more family-oriented cars. Shepard and Grissom used to constantly drag race in their Corvettes, but Grissom cheated one year when they leased identical Corvettes, by having the dealer tweak his to make it just a little faster. The three Apollo 12 astronauts even got matching gold Corvettes that had a black pattern added, along with their name and crew position being painted on the driver's side door.

So, given that they only mentioned it the one time, and it was just a momentary part of that episode, it's not that significant of a product endorsement compared to shows that prominently feature specific vehicles in every episode (and almost always include extra dialogue about the cars when they change models). After all, this was a program that ran for almost a full decade, and only ended due to public outcry after the Apollo program drew to a close.