For a vehicle, presumably from “GP,” meaning general purpose.

Is that true, or folk etymology?

Which came first “Jeep” as in the vehicle or “Jeep” as in “Eugene” from the “Popeye” cartoons?

Popyes Jeep came first. The GI’s made the connection of GP to Jeep. Eugene was never his name till those atrocious tv cartoons that changed Bluto to Brutus.
there was an official govt. malady known as Jeep Butt to the GI’s too. It was only indirectly related to the rough ride.

“Pardon me while I have a strange interlude.”-Marx

Nobody really knows, but here’s some info:

If anybody would know it’s beatle. how’s sargent snorkle? I thot i was gonna find out it was never called GP. Next thing you know I’ll find out that the bazooka theory is all wrong.