Batman has his batmobile. So, really, why can't Doctor Who get his own TARDIS-mobile too? Sure, TARDIS is a vehicle of sorts already in itself, but it's no car. You can't exactly take it out for a spin in the streets so you can go cruise for girls, can you?
TARDIS is fine for time and space traveling and all, but when the Doctor wants to go out into the real world and socialize--well, he needs a real car.
With this in mind, Deviant Art artist ~Ificial-Art came up with this Scion xB and TARDIS mash-up that can seat up to a hundred people and fit an indoor dance flooor. Because, you know, the Doctor likes to dance. While he's driving. Yeah, he can make that happen.
The bad news? I think it's pretty obvious that the TARDIS-mobile is merely a concept. A drawing. Just a figment of someone's imagination.
But if anyone can make it real, it's the Doctor. Or someone with oodles of cash to burn. Here's to hoping.