Good way to farm Rings?

#1Tanooki_YoshiPosted 4/19/2013 8:32:39 AM(edited)
I've just beaten both stories in Sonic Riders, but now I'm looking for an easy way to amass Rings in order to purchase all the gear at the Shop.

Does anyone know a good way to do it without having to go through Story Mode again?
Two is company and three is a crowd, four is an unruly mob, big and loud!