To get a good start and a full blue eco tank at the begining of each race, right when the light hits green and is a go press forwards and X and you will boost and gain a full blue eco tank. the timing has to be good to get it.
Go to the Secrets shop and do the secret character search for these drivers:
Jak I- have a Jak and Daxter save file on your memory card
Jak 2- have a Jak 2 Renegade save file on your memory card
Jak 3- have a Jak 3 save file on your memory card
Ratchet- have a Ratchet: Deadlocked save file on your memory card
Complete The Game to unlock both drivers
Hook up the psp to the ps2 with the daxter video game by usb cable. And at the secrets shop you can get daxter cart for free.
Play as - How to Get Them
Daxter - Play over five hours of game time to unlock Daxter in Exhibition mode for purchase at the Secrets Shop for 50,000 Orbs.
G.T. Blitz - Complete the game.
Klever - Win the Beachfront Drive Circuit race in Adventure Mode to be able to unlock Klever in Exhibition Mode.
Pecker - Play over ten hours of game time to unlock Pecker for purchase at the Secrets Shop for 60,000 Orbs.
Ratchet - Have a saved game file on 'Ratchet: Deadlocked' on your memory card to unlock Ratchet at the Secrets Shop when you select the "Scan For Secret Characters" option.
Complete the game to 1005 and you will see the Sandshark vehicle in the Items Shop.
to unlock the naughty dog (a super fast car decked out in the naughty dog signature colors) you have to earn enough game completion and buy it in the secrets shop.