Guy's, I think I found a good way of getting your TR99 done. I was slogging away doing single player practice trying to put the four clean laps together but it was very inconsistent, would do like 8 clean laps at Nurb and only get 2 medals.
I had six tracks that needed the third medal, so I set up a single player 10 minute race against the AI at midnight. Set the AI at 85, (you'll do a good pace keeping with them), but set the Aggressiveness at 25 so they don't take you out. Have at least 9 opponents and start last, (staying close to the AI in front and passing helps SA rating). As long as you do clean laps, which I found easy to do for some reason, you should get all 3 medals. 10 minutes was long enough, even just 4 laps worked.
The only thing I can't say for sure is if you start the race at a track where you don't have any medals if it will give you all three but it should. Like I said, I already had two medals at each so not sure if that made a difference, but worth a try.
An added bonus is I was picking up 1 safety point at each race as well. Seems like SA70 and TR99 will unlock some good rooms.
. It's good fun and so far I been able to win enough Fame to buy both super duper exclusive cars so there. Ha.
Still have a few tracks to rank up on... been playing too much ACC on PC. 
