I Used To Work At A Fiat Dealer, So You May Come Across Common Problems Such As Wiper Linkage, Rocker Gasket Etc...
Check The Service History To See If They Have Already Been Done, The Car Should Come With 2 Keys, And Ideally A Keycode Card.
Which Is Basicaly A Credit Card Sized Card With, Key Code On It, Thats What A Fiat Dealer Would Need, As It Has A Code Required By Them To Program A New Key.
Although Don't Frett If It's Missing, As It Can Be Replaced For About £10- £15 On Top Of A Replacement Key.
Which Is About £50 Mind You!!
The Electric Power Steering Can Go Faulty Too, Which Is About A £500+ Job At A Fiat Dealer.
Make Sure The Warning Light On The Dash Board Light Extinguishes Once The Engine Is Started, And The City Button Works, Or If It's Not Working At All!!!
Coil Packs Can Go, Which Can Result In Poor Running, Misfire, Staling Etc.
Ther About The £40 Mark.
Also Check For The Usual Knocks And Scrapes, Kerbed Wheel Trims, Etc, Fag Burns, As That Can Give A Good Indication Of How It's Been Treated.
Look Out For If Its Got A Very Shiny Steering Wheel And Gear Knob, Or Heavly Worn Seat Bolsters As There Mileages Can Be Easily Clocked.
Also Make Sure The Chrome Coulored Paint Code Sticker Is On The Bottom Edge Of Bonnet, Near The Wiper Motor.
If Thats Missing It's A Possible Sign The Car Has Been Damged And Repaired At The Front.
Over Than That, There Pretty Good And Are No Worse Than Any Other Model Of Fiat Or Any Make Of Car.
Hope That Helps!!