I dont have central locking in my mk2 and i always have to put the knob down when the get out as it doesnt appear to lock when the door is open therefore the passenger cannot lock the door when getting out.

Is this normal?

It's normal. All Fiats have this "prevention mechanism" (at least I call it that way) so you won't forget your keys in the car and lock yourself out of it. This works only for the front doors.

Thanks