A few cars actually have bed space built in. Let's be clear here: we're talking about cars with proper, purpose-built bedding, or at least seats that fold completely flat to make up a bed.
2011 Citroen Tubik
The decidedly odd 2011 Tubik concept from Citroen feels a bit like a luxury flat on wheels. The middle and rear sets of seats are designed to fold completely flat, creating a set of aeroplane-style seats that you can sleep in. Citroen has even made a stab at creating a post-sleep breakfast theme, too, by making the Tubik look like a giant toaster.
The memorable 1970s UK advert for the Maxi declared it was five cars in one: family saloon, estate, school bus, removal van and... overnight camper. 'Yes, you can sleep in a Maxi,' said the ad, 'because the seats have been designed to convert, quickly, into a comfortable bed for two.' Clever stuff but advertising regulators might have something to say about the 'comfortable' claim these days.
Like the Austin Maxi, the Renault 16 had multi-adaptable seating that the French company advertised as converting into a double bed. The fact that the 16 had a column gearchange also meant there was no gearstick to cause unintended midnight misunderstandings.
The symmetrical Janus, built by motorcycle maker ZUndapp in Germany in 1957-58, is the perfect car for divorcing couples. The rear seat passengers sit with their backs to the driver, separated by the engine, and there are individual front and rear doors to get in and out. Zundapp even thought about marital reconciliations: all the seats fold down to make a double bed.
To create the California, VW takes its Caravelle and makes a seven-seater MPV that also turns into a camper. The rear bench seat folds to make a two-berth bed across the car, while a pop-up roof gives access to another double bed. You even get pull-down blinds and covers for the windows to ensure total privacy.
Alongside VW, Mazda is one of very few car makers to build its own factory camper. The wonderfully named Mazda Bongo is an eight-seat MPVs whose central and rear rows of three seats each can be folded flat to make a double bed ideal if the jungle fever takes hold. Some Bongos even have an 'Auto Free Top' an electrically operated elevating roof that can be used as an extra sleeping compartment.
The original Fiat Panda of 1980 was a paragon of design simplicity. A great example of this was the hammock-style rear seat which could be folded into a V-shaped luggage scoop, or folded flat to make a (rather cramped) bed. The seat covers were even removable and washable so if there were any, ahem, night-time accidents, it was no problem.
The Honda S-MX has achieved a cult following even in countries where it was never sold because it's so unique. The front and rear seats are both benches, and both can be folded completely flat to make a double bed. Surfers have latched on to the S-MX as a result.
The original Saab 93 was designed so that the rear seat squabs could be rearranged into two beds. Considering this was a two-door saloon, that was a real feat, yet it was reportedly big enough to fit the averagely tall Swedish gent (and lady, presumably).
OK, the Aztek could well be the ugliest car ever made, but it was one of very few that had sleeping in mind. Supporting Pontiac's marketing of the Aztek as a youthful, active-lifestyle vehicle, one option was a tent package that fitted over the tailgate, complete with an inflatable mattress. Pontiac even offered a built-in air compressor to blow your bed up for you.