Soap, water and a brush would be my recommendation, or indeed something else that's appropriate for (basically) uncoated aluminium. It's going to be hard keeping the wheels pristine without some elbow grease, but I suspect that the Flitz polish followed by some beeswax would mean you could get away with polishing just a few times a year. Aluminium corrodes, that's just the way it is.
Lots of Roadster pilots (well, some Roadster pilots) here have powdercoated their wheels for both looks and ease of maintenance.
I'd love to get mine coated too but nothing would look right to me on the R3T except chrome and untreated polished metal... so since
http://www.calchrome.com/CalChrome-Clear-Coat would set me back a grand easy with shipping and the like halfway around the Earth, I guess I'm polishing and liking it.