Teams aren't teams in Formula One, they're constructors. It's part of the definition that makes F1 what it is: each team builds their own cars. Engines can be obtained from a major manufacturer – though BMW, Renault, Honda and Toyota have joined Ferrari in doing it all in-house – but in theory, at least, each team is supposed to have its own chassis.
That notion, however, is coming under fire. Red Bull and its satellite Scuderia Toro Rosso used a common design this year. Super Aguri is preparing a chassis acquired from its engine supplier Honda, and newcomer team Prodrive just announced it'd be fielding cars bought wholesale from McLaren. The potential result is being billed as "super teams", essentially giving several racing outfits four cars instead of two.
The jury is still out at the FIA as to just how "kosher" this development is, and in the process the fates of several teams lie in the balance. Never prepared to sit on the sidelines, Ferrari is rumored to be considering providing a complete car instead of just an engine to one of the teams it currently powers, though while the motorsport press is suggesting Toro Rosso as the potential recipient, its tie-in with Red Bull Racing might leave the recently sold (and soon to be renamed) Spyker team a more likely partner. For McLaren's part, however, having two teams in which to split their star drivers could prove the most convenient of all.