Ok, now that I got this bloody thing without being part of a boost session I can offer a suggestion for people who want to attempt this by racing randoms from the 24th position. Fun!
To increase the odds of being in the 24th position this is what I did....
1) When your lobby reaches 24 players or is very close select a player and select show gamer tag.
2) Select join and join game as soon as the lobby is full (you can still see lobby size with the side panel). I usually did this around 20 seconds left on the intermission if possible.
3) Hopefully no one leaves and the game starts.
4) This will not get you the 24th position 100% of the time but I had a very high success rate. I would say 85% of the time I would be 24th (Just noticed this was a similar finding to Cecil Kilmer within an organized session) or I would be at the front of the pack which was nice for easy wins (Usually when it was more then just I joining last minute this occurred so is an added variable).
I have also done this twice before and the game seems to crash as the car pulls up to the garage. Just a heads up before anyone gets too excited.
The attempt I believe I got it on I actually saved the clip in disgust as it did not pop up. However, the next day I turned the game on and Thru The Pack was mine. It has been an emotional journey