petrol smell when filling tank to top

[bram248]

I became the proud owner of a 3.0i sport x5 on wednesday and filled the tank up to get the car home, when i got home i could smell petrol outside of the car.I used the forum and managed to track down the source of the petrol to be coming from the inspection hole under the back seat.
I have a couple of questions on a righthand drive what is under the backseat behind the driver the petrol pump or the fuel level sender?

And also it had one pipe with a crimp on to the plastic housing and then an electric style plug but there was another plastic housing should there be any pipe attached or is it just a breather of some sort.

its just when i found the problem there was a couple of cm of petrol sitting on top of the fuel sender/pump and i normally have the kis in the car.