So my formula was the following for each Wii Cup Circuit:
Mushroom Cup - Diddy Kong with Mach Bike
Flower Cup - Peach with with Super Blooper
Star Cup - Mii with Super Blooper
Special Cup - Mii with Super Blooper
All this was with Automatic drift. Overall the bikes seem to be faster and I like to wheelie, but I was just getting pushed off the tracks too much with the bike, going with a quick kart seem to help with that respect. You can win and get stars with just about any character, this just worked for me.
So here is Dry Bowser, he is very bad ass looking and makes cool noises when you drive him. Now I just need to dig into the Retro 150CC cups, which I think are a little easier and open the Jetsetter. Then also I should have stars on all tracks that I have raced, so I then should have a star next to my name online. I have unlocked Mirror Mode but have not raced. I am resisting the temptation so that I can get the star rating and then just get one star at a time in Mirror Mode to preserve that ranking.