The Romini lives up to this. It was a tiny caravan built by Romahome, the motorhome company on the Isle of Wight. Only about 200 were ever produced but they're a neat little box, with sleeping room for two and a basic kitchen. Only 3m long and less than 400kg in weight, they are a doddle to tow.
There is an excellent example on eBay at the moment (click here for link). One of the last ever built, it has an excellent spec and comes complete with awning - all for a buy-it-now price of £3500 or offer.
Thanks to eBay seller inkspot04 for use of the pics.