Need Help with PS2 Spy Hunter gameplay!...

[dave4shmups]

OK, no one on Gamefaqs will help me (big surprise there), but I am having big trouble with the turbo function. You're supposed to tap the acceleration button twice, but it rarely works for me.

I would appreciate ANY advice on this from anyone who owns this game. If I can figure out how do this properly, then I won't get rid of this game.