Starting to sound like maybe your ignition switch has a problem.
turn the key to the on position, then try manually cranking the starter by connecting the solenoid wire with the battery wire, on the starter. if you're not sure how to do this, say so.
if it starts by 'hotwiring the starter' but not with the key....i'd be buying a new electrical end of the key switch.
i just got a cabrio myself..not an expert...yet.