I used the following link to change to the rice video plugin manually, however it does not perform as well as the other plugin, so I reverted back.
https://code.google.com/p/mupen64plus/issues/attachmentText?id=433&aid=4330002001&name=mupen64plus.cfg&token=40e6269250310cd39245a2e317e6a1cb
@robofruit does your Mario kart work good with multiplayer?