You must score enough points in races to place yourself in 1st, 2nd or 3rd. Points awarded from races are as follows.
1st - 10
2nd - 8
3rd - 6
4th - 4
5th - 3
6th - 2
7th - 1
8th - 0
try to win all the races
You have to get at least 1 star in every 150 grand prix. Its not easy.
There is no other way.
You have to get at least a one-star rating on all the 150CC Retro Grand Prix cups
get the last star by getting red coins
easy all u have to do is beat all the cups in 50 cc 100 cc and 150 cc and party u have it or search action replay cheat codes for Mario kart ds ................
Ehh... Just win all the laps.
you need to do a lot of stuff on 100cc and 150 cc or 50cc. mostly 100 and 150cc though
you have to complete the 50 CC, 100 CC, 150 CC, and mirror and unlock all the characters
You have to beat every level except for the mirror courses. Trust me I know because I own the game and I have beaten it (except for the missions XD)
50 cc: Special Cup gives u Dry Bones. 50 cc: Lighting Cup gives u Daisy. 100 cc: Special Cup gives u Walugi. 100 cc: Lighting Cup gives u a 3rd kart 4 every1. 150 cc: Special Cup gives u Mirror cc. 150 cc: Lighting Cup gives u 4 more karts (making 7 karts) 4 every1. Mirror cc: Im not exactly sure which cup but either Special or Lighting unlocks Robot Operating Buddy (ROB) who is the best caracter.
When you get 150 star you go outside with luigi and go to the cannon, then go on top of the castle and get the rabbit