It looks like unlocking any other character or vehicle or anything of that sort, except with Bowser Jr. there.
If you're also wondering how to unlock Bowser Jr.: Complete all 100cc Retro cups with at least a one-star ranking.
you have to unlock the different karts by racing the world cups.
Like Mario Kart Double Dash you can unlock him and in some Mario Marioparties.
No Rosalina doesn't. But the stars are like her kids... kinda
Retro Cups are courses that have been in previous Mario Kart games. Like DK's Jungle Parkway N64, Bowsers Castle GBA, Yoshi Island DS, and Skyscraper N64. shell, banana, leaf, lightning are retro cups
You complete the game then you erase the whole file. When you complete the game again you will unlock: Baby Mario Baby Luigi Baby Peach Bowser J.R and Starman (Has a star on all the time and is shaped like a star.)
Yes, If you would like to unlock items
personally, i recommend Yoshi in his egg 1 kart. but you should go with whatever you are best with.
No! Did you see a list like that?!! No!You did not!
THEY LOVE
Depends, different vehicles have different requirements. Same with characters like Rosalina.
Yes, do you? me two i like it
Birdo isn't featured in Mario Kart DS.