So much thread try to run GH and RB to play DLC and it come with 3-4 way to work i guess
and also some problem come from flash drive or sd card need to be 2gb even need shop file to work which i not sure is real
Using USB Loader or WillFlow and dlc by mariocube with install wad by wiimodlite or...
Cruisn on the Wii is one of my personal examples of that, it's considered one of the worst games of all time, I loved it and completed it several times.