I think those aircleaners are designed for the dealer to be able to book in Service work. When you want to build "better" v-twins, it gets complicated..
Terry, I did a quick search one day for Kicker equipped BMW RT's.. and there was scads of them... maybe not in OZ.. but a lot of the rest of the world...just saying..
No worries Frank, I thought about converting mine when I first bought it, but then I found that I could buy the 450W alternator conversion which replaces the OEM 220W system, so no need now mate, I bought and installed the new alternator (rotor, stator, diode board, brushes, springs, regulator etc) and now that it pumps out 13.5V at 2000 RPM, I should never have a flat battery again! Cheers, Terry.