If you have the code card you can follow the emergency start instructions to start the car. If not take your red key, some ID and your V5 to a Fiat dealer and they'll get it for you.
You will still need to take the red and blue keys to a Fiat dealer to get them put back on the cars system. Don't stop the car otherwise you'll have to do another emergency start.
85% of Marea HLX drivers have speeding tickets.... lol they'll have to catch me first.