nondeplumage: Flying cars are achievable with relatively small energy output. Playing with space/time requires a bit more than an engine, so one's a hell of a lot more likely to happen than the other. But in keeping with science fiction tropes, they both can lead to untold deaths and therefore is an awesome reason to bring in the space marines.
Yeah, what was that teleportation poem in Hitchhikers Guide to the Galaxy again?
Oh, right: "I teleported home one night with Ron and Sid and Meg, Ron stole Meggie's heart away, and I got Sidney's leg." Also, I bet it's much more fun flying than being teleported, seeing how the latter is described as "not quite as fun as a good solid kick to the head".
Still, it'd cut down transportation time to pretty much nil, which is always a plus - except possibly when accounting for jetlag.