went and bought a full tank of fuel yesterday and as I was driving around and getting in and out the cinq I was seeing and smelling fuel! I eventually realised that it must be coming from the over flow pipe! And after 30 minutes or so it stopped! But I did panic not wanting a big fire ball has any other had this problem? I stopped at the first click on the pump!

Evidence

Have you checked that it isn't through the seam in the tank?

Yes! The tank is new ! I was thinking it was a pipe that had come loose from the fitting at first!

Had the same thing -N reg Cinq Sporting losing fuel but only when i brimmed the tank.
Turned out to be a tiny pin hole in the hose going from the filler cap to the tank, only lost fuel when the fuel level was high & it sloshed about enough to travel back up the pipe.
Easy enough to whip the wheel-arch cover off & check. If there are no breakers near you https://www.fiatforum.com/members/jiminwatford/ will probably be able to post you one asap.

Ye had the same here. It was a pin hole in the larger of the breather pipes.