Success!
Copper pipe fixed to garden ose. You need to keep the downward pointing part of your copper pipe short. No more than half inch (as Conan mentioned!

) or it wont fit in. (ooh err missus)
Also bend the copper so you can tell when your downpointing end is pointing down. Get it under and wriggle it about.
Sudden whoosh and all the water emptied under the car in about one second!
Brilliant!!