Wikipedia definition - In North America , tailgating can refer to the (often celebratory) practice of eating and socializing while perched on the open tailgate of a vehicle (though many people participate even if their vehicles don't have tailgates). This may include barbecueing and is usually related to sports fans preparing for Canadian football , ice hockey , or American football games. These events are also known as tailgate parties.
Here's a collection of links to cool tailgating vehicles, trailers, busses, BBQ trailers and parking lot parties!