Are you in rust belt?
Any work done recently?
How many miles on your rig?
Fuel line leak is uncommon and unmistakable smell. Are you sure it's gasoline?
Fuel lines are on DS as are return lines. Leaks here tend to be forward of drivers door, but can travel back.
A common leak is from front differential oil seal, there's one seal on DS and one on PS. This would be gear lube which has a very pungent smell. To me it's the worst smell of all fluids. This take tools to check level. This leak is more forward inline with wheel, but will travel back.
Other leaks in this area are from recent oil changes, where oil filter not seated properly, drain washer not replaced, or oil spillage during fill up. These too are further forward, but can travel back.
Leaks travel back and down generally (parked on flat ground). I remove engine cover and both undercarriage covers. I then like to take lots of really good pictures, following leak (wet area). Then use a PC to zoom in on pictures making sure I've got everything. Once I think I've found and have all the pictures I need, I degree & power wash. Then watch closely for leak to reappear, pinpointing it's source(s).
