Franco, I am not an expert by far, but was struggling with fuel leaking, so from practical viewpoint:
1. If you can locate (and it seems like in your case you could) the leak by looking at the car as it stands vs. where the fuel pond on the floor is. From your description - maybe it is the supply or return fuel line connection to flexible hoses near the fuel filter may be leaking and fuel just floating down the pipe, dripping on the floor.
2. Then you use the wet finger menthod. Slide your finger around every connection there is in a systematic way, paying particular attention to the part of connection facing down. I would follow the fuel flow so that you do not miss anything:
- fuel supply line (close to left inner fender) connection to hose
- hose connection to filter inlet fitting and fitting vs. filter housing
- very important - bottom of the filter housing
- filter housing cap screws
- filter housing cap vs. the main body
- filter outlet fitting and hose
- CSV pipe connector with all fittings and hoses
- FIP inlet
- FIP outlet
- damper in
- damper out
- damper housing
- return hose connection to return pipe
You will find it.
When fixing - pay particualr attention to safety rules while working with fuel.
You have the picture here
