How do you get b dasher in Mario Kart wii?

for Mario Kart 7 notice how all of the kart pieces are from getting a certain amount of coins. well there is no exact amount of coins you need for it you just need luck and you might get it! here are a few tips on getting coins: try doing community races or do a couple of online races. a hectic race will possibly make you forget that you are trying to get a kart piece of some sort. hope this helped and good luck!