I've driven many races so far and got almost every cup completed
but I still don't know how to make stunts when I drive over rampages

if anyone knows how to do it ... please tell me! I would really appreciate it

If your using a gamecube controller then you press up on the d-pad just as you leave the end of the ramp, if using the wheel or wiimote you shake the controller when you leave the end of the ramp.

yeah nice! thank you for telling me this ... it's alot more fun if you know how to make stunts

Yeah the stunts really make the game for me, they look so cool and the speed boost is always nice