Spidey-sense doesn't tingle...
Can you trace the line from the front to back and not see anything obvious?
If you disassemble the interior behind the drivers seat (sounds scary but is trivial once you've done it a few times) you can access the top of the fuel pump assembly. May be worth a look.
Do you have tools to check fuel line pressure? If you put the gauge on and it bleeds off pressure over a period of time then either the check valve in the fuel pump is bleeding back to the tank (but would not explain the smell) or there is a leak elsewhere.
My gut says inspect where the injectors mount to the fuel rail and then the fuel pump...
Or just take it to Ralf and the b'ys.
