They had plenty of Mario Kart so I bought one. My WiFi dongle shipped yesterday so I will try Best Buy or Media Play next week for AC.
Hope it works for you. I still get that "Please Plug in the Nintendo USB Connector" error while it installs. Luckily (I guess), many others have been getting that error. And it's apparently pretty random of an error too. My brother's computer - which is essentially the exact same as mine - installs the USB Connector and it plays flawlessly. And I've been part of the many people that have tried to find a fix.
Still haven't found one either. Though, by our monumental post about that problem in the forums, apparently Buffalo (the makers of the stick) and Nintendo are coming up with some downloadable drivers to get the issue fixed.