Yes the filler (on front face of gearbox) is just about accessible if you loosen the heatshield over the dualogic fluid reservoir and move it out of the way as best you can (assuming this is dualogic and not a "proper" auto). The plastic reservoir has a "cutout" moulded into it that allows access to the hex plug. Bit tight though...as ever, so near and yet so far in terms of Fiat making life easy for the hapless mechanic.