reposting cause it doesnt look like I can edit...if you're trying to upshift fast in normal driving...don't even try because it's not going to be smooth. Not sure in which situation that you want to shift fast in but when you press on the throttle pretty hard, that is when you can start shifting fast at lower rpms...as in instead of tapping on the accelerator to make the revs climb, go WOT or near it to about 4krpms and try shifting fast...should be smoother than trying to shift at 4krpm when you're on the gas lightly.

'03 G35c DG/G 6mt, full options