I also has a fuel smell problem on my A32 3.0L. I only noticed it after I fill the car up full. After some time when the level drops the smell no longer there. I also notice fuel dripped on the floor after I parked the car when the tank is full, no problem when the fuel level dropped.
So I check out all the hoses and they were ok. So I removed the rear seat opened up the metal cover covering the fuel hoses and pump + fuel sensor wiring. Had the car with full tank of gas and guess what I found that there was small hair line crack on the top of the fuel gauge sensor. This is the one where the fuel pump and gauge wiring couples to and the fuel supply and fuel return hoses enter the tank. The whole assembly is made of plastic and there was a very small crack. Fuel was coming out of the crack and filled up the whole top of the assembly. Had the car running and could see bubbles coming out from the crack. So when the tank was full to the brim the fuel was coming out from there and the internal pressure also pushes the fuel out. So when the fuel level drops. No more problem as the leak is from the top. So I dried it up and super glued the crack and so far so good. No more smell and no more leak.