To my knowledge (Assuming your playing the GC version) You hit one of the shoulder buttons (R I think, I havn't played in a while) and let go of 'A' because if you don't.... Then you won't. If you have Basic configuration on the gamecube then you press and hold (R-button) to drive and then for drift races the best thing to do is NEVER EVER let go of the accelerator, insted use the brake (L-button) and E-brake (A-button) to cut corners. keep goin' side to side on straightaways. as you approach a turn, let go of the gas hit E-brake real fast then floor it out of there but don't forget to keep "swinging" side to side to keep your drift goin'. remember you cannot keep a drift you started waaaay back there around the next corner, it's not possible. if you want to keep you drift points stop your drift before you get to the corner. trust me, it will save you alot grief, if you do what have said.