Can 4 friends play Mario Kart Wii online on 2 consoles?

My sister and I are trying to play Mario Kart Wii online with 2 of our friends. We tried connecting by each going to the 2 player WFC, but it wouldn't work. When we went to 1, it did - but that only allows for 1 on 1 play. Does anyone know how to do it so that each console can have 2 players for 4-person play? Thanks.