Gloves?
I don't think this is going to work as an addon something. Think about the power demands of something that converts electricity to heat and then route the powerwire out of the way of getting hooked on anything then making it capable of rotating 2-3 revoltions in each direction. It would be interesting on its own to see how the Jag does it using like a clock spring or the GM SEO coil type setup with sliding contacts. Any sort of kit is going to have to involve pulling the steering wheel I would imagine then using a sealed rotary collar behind the wheel that doesn't give off EMI to mess with the factory controls and provide enough power to run the heating elements. The design of the cover is realtively simple, some sort of rubberized non slip backing, thermal insulation binding material that the heating elements are imbedded on the surface of, then a conductive later on top of that that binds the whole back assembly stack up to the leather cover. Run a power cord down one of the steering wheel spokes to the hub where you would have to drill or otherwise make a hole to get to the central coil assembly around the hub which would then have to be wired on the otherside to the cars power through a switch. I can design it I guess but it would be near impossible to capitalize on without a direct liscence from someone since its so darn simple I couldn't sue someone for changing the steeringwheel stackup or something and making it on thier own.
