i have heard of a process called nicko-shine it is electroplating for alloy but it is not cheap. it is better than polishing because after a while polished wheels go all smoky and need repolishing. the nicko-shine wont and it is easier to clean too. i think they use this process on all those aftermarket chrome mags.
I found a guy in Albury that does Truck wheels, I was looking at getting my AUI XR8 rims chromed..
Didn't relise that they actually dismantle the rim to chrome them, basically machines out the edges, goes through the process then welds back together. I wasn't too sure about the structural damage that may do, so I decided not to do it...
The bloke who referred me said he has seen some truck rims done by this guy and they looked good.
Shooting from the hip he gave me a price of $160-$200 a rim but the guy who does the quotes wasn't in and will be in next week.