EU block exemption rules that have been in place for many years mean that you don't have to go to the manufacturers' dealers for servicing. You will however need to ensure that the parts used are up to manufacturer specification and that your invoice (and it should be a VAT invoice) confirms this should you ever need to go back to Fiat for warranty issues. Many people have the car serviced by the dealer during the warranty to avoid any warranty problems or to be more precise to avoid the inevitable hassle when claiming under warranty when the car hasn't been to the dealers. In your case it would be just the one service in the 3 year warranty period. Dealers servicing charges vary quite a bit so you might find a competitive rate at a dealer vs an independent.