there are only 3 segments, i think it's second or third, can't remember correctly
The 100% uses it at the start of segment 11 and the any% is near the minute mark in Segment 4. I'm not 100% sure whether the replay is from a previous segment in either case. Both runners use them once for the run as far as I know. Don't know if any of this info will help. I'm not crazy about the trick but it was legal (I think) when I verified one of the runs. I don't know if the trick is possible in the other GTA's (I play the PS2 version).