Green is clean, Red is DQ. Simple as that for this competition.
But the cheating I'm talking about...
Turn 1, has the right off to the left, you can ride up on and potentially have all 4 on the 'run off' which is considered dirty by WRS standards.
After the hairpin, there are 2 left turns, the second left turn is completely concrete on the inside and you can cut across that to shave some time.
Then, immediately after than, there's a run off to the left that you can use to get ready for the next corner.
Moving to the exit of the second tunnel, right as you begin the bridge, it's all asphalt to the left, and you can swing wide out there. But the white line is clearly to the right and you can easily have all 4 tires to the left of the line, which is considered dirty.
Then the last spot, is the 2nd to last corner, where you ride that concrete slab after the tight ess curve, leading into the final corner to the straight. Again, considered 'off track' by WRS standards.
All of these combined can probably net you 1.5-2 seconds if used correctly.
There's another way to use the entire track to your advantage, but I won't be giving that info out. I haven't used it yet for any of my lap times, as it's unnecessary.
But, all of the above are considered 'legal' by this competition. As long as it's a green lap, it's acceptable. It really doesn't matter if you cheat or not, as long as you consistently cheat for every car you test. I just find it far too difficult to change my entire line for a single competition, when the online world has forced me to maximize every and any limit within it. So unless GT5 flags it as red, or the online rooms dock you a short cut penalty, then it's fair game!