L322 2004 Petrol

I filled up the old girl today with petrol, to the brim, and noticed as I left the petrol station
that a puddle of petrol was under the car, I pulled over and told the manager and they very
quickly covered it with sand, whilst they were doing that, I looked under the car to try and
find the leak, but really couldn't see where it might be, am now back home and after 30 mins
driving there is no petrol leaking on my driveway, so I am guessing the leak may be high up
somewhere in the 100L tank, or from the filler neck to the tank, loking for help and ideas
on what might be obvious, but I have missed it

I saw this on the forum, but a diesel, but probably the same for petrol "The full tank breather that runs from the tank to the filler cap neck gets crushed by the body work / chassis and leaks fuel out all over the place when you tank it right up", but you have to remove the exhaust and drop the fuel tank to fix !