Alfa Romeo 156, 147 and GT
The washer bottle is inside the left hand front wing as you face the engine bay. It has a dark blue flip top approx 1 inch (20mm) in diameter, DONT confuse this with the header tank for the coolant which has a screw on top and is slightly larger.
Flip the top on the washer bottle put a funnel in the tank and top up with a 50/50 mix of screen wash and water. If you are sure your container is clean you can remove the filter in the top of the screen wash bottle and it will fill up more quickly.
On a MiTo the screen wash bottle is just behind the left hand headlamp (circled in the photo)
As it is on a Giulietta, again circled in red behind the headlamp