A quickie money-saving tip here; nip into your local Asda, go to the car/diy section and snap up the 500ml spray cans of Turtle Wax "Black in a Flash". £2 a can! It makes Hypalon look like new! Check out the instructions too because if you prefer a matt/satin finish it can do that too, just apply differently.
Oh, and it smells luverly!