I'm assuming you know what Scrap heap is about? Anyway it was an all stars ep and one of the challenger teams were cops, they used a Micra that had been seized as their base for their creation.
The aim was to play 'blower soccer' so the contraption had to be able to move around easily and have some sort of giant blower to blast air at the ball to push it around instead of kicking it.
They took off the back wheels and put a shaft down the center of the car probably about over where the back wheels would have been and they put like mobility scooter wheels on it... by having the shaft turn they got rear end steering which made it extremely manuverable.
But they went downhill from there, they had a dodgy blower system that was electric and very weak.
I'm sure there'd be footage of it on youtube.