In this video some guys from New Zealand attach helium balloons to a car until it floats away. Unfortunately, no one is in the car when it floats away. (Though that would have been a good update on the legend of Lawnchair Larry.)
Of course, the video is fake. TV3.co.nz reports that it was digitally edited to remove a crane, which is what actually causes the car to rise into the air. Also, the video turns out to be a viral ad created by Ford "aimed at selling Ford cars to generations X and Y."