I never did the wheelie trick in GT3, but my co-worker had. We spent a good half hour or more trying to get a vehicle to wheelie in GT4. I earned the Escudo by completing the second-to-last Special Conditions event. We bumped it up as much HP as possible--still only went to 1,100-something--and tried to tweak it appropriately. The vehicle started to lift off the ground at around 210MPH. In the straights, with NOS, we could only get it to about 250-260. It'd wheelie definitely, but it'd rock back and forth instead of pulling upright. And sadly it never accelerated past 260ish. It probably only went up about 25-30 degrees off the ground (opposed to the near-90 degree wheelie my co-worker described about GT3).
We will try again.
We will try again.