Successfully complete the indicated circuit with a time less than the target to unlock its development team ghost racer, with the corresponding best time:

Nitro Cup: Airship Fortress: 2:10:000
Nitro Cup: Bowser Castle: 2:20:000
Nitro Cup: Cheep Cheep Beach: 1:45:000
Nitro Cup: Delfino Plaza: 1:55:000
Nitro Cup: Desert Hills: 1:35:000
Nitro Cup: DK Pass: 2:15:000
Nitro Cup: Figure-8 Circuit: 1:38:000 (1:36:481 best time)
Nitro Cup: Luigi's Mansion: 2:00:000
Nitro Cup: Mario Circuit: 1:57:000
Nitro Cup: Peach Gardens: 1:53:000
Nitro Cup: Rainbow Road: 2:17:000
Nitro Cup: Shroom Ridge: 2:06:000
Nitro Cup: Tick-Tock Clock: 1:55:000
Nitro Cup: Walugi Pinabll: 2:24:000
Nitro Cup: Wario Stadium: 2:15:000
Nitro Cup: Yoshi Falls: 0:58:000
Retro Cup: Baby Park: 0:55:000 (0:50:920 best time)
Retro Cup: Banshee Boardwalk: 2:15:000
Retro Cup: Bowser Castle 2: 1:53:000
Retro Cup: Choco Island 2: 1:02:000
Retro Cup: Choco Mountain: 2:16:000
Retro Cup: Donut Plains 1: 1:09:000
Retro Cup: Frappe Snowland: 2:09:000
Retro Cup: Koopa Beach 2: 0:55:000
Retro Cup: Luigi Circuit: 1:37:000 (1:29:759 best time)
Retro Cup: Mario Circuit 1: 0:51:000
Retro Cup: Moo Moo Farm: 1:18:000
Retro Cup: Mushroom Bridge: 1:31:000
Retro Cup: Peach Circuit: 1:13:000
Retro Cup: Sky Garden: 1:45:000
Retro Cup: Yoshi Circuit: 1:49:000