YOu could do it for less than £200
Ingredients:
1 Bottle of Coke: 99p
1 box of Tissue: 50p
1 Passenger: Free
this is how you do it....
Step 1: BIG BOTTLE OF COKE -RIGERROUS SHAKING
Step 2: PASSENGER - OPEN BOTTLE AT APPROPRIATE GEAR CHANGE
Step 3: CLEAN UP - REPEAT WHEN NEEDED.
sorry for the piss take, but it does seem a silly pointless idea, but if you want to develop the idea and you have the money go ahead.. I know many many nova, saxo, corsa , likewise drivers that would pay hundreds for something like that to go on their neoned up sheds.
Si