I also get a strong petrol smell waft through the window when i pull up.. no obvious signs of leakage. Mine too appeared after the car was mapped but i also de-cat'd the car just before so..
I tend to notice it when coming to a halt after hooning it, I imagine looking at the shootout graph and the AFR reading that this is because the car is running low 10's under hard boost I.E very very rich. Normal driving around town doesn't seem to do it, especially from cold, although now thinking about it i'm not sure
any ideas welcome