Well, someone does. It's the Form-A-Funnel from Griot's Garage (www.griotsgarage.com), a simple design consisting of a thin, malleable piece of aluminum alloy encased in thick, pliable Nitrile rubber. As manufactured and delivered, it's perfectly flat, but it easily can be molded into just about any reasonable shape to carry fluids into or out of their reservoirs. You just bend it into the desired configuration using your hands, and it retains that form until you either mold it into a different shape or flatten it out again. Oil, coolant and other liquids won't penetrate the rubber surface, so it cleans up easily when you're finished with either a rag or a cleaning product such as contact cleaner.