If you can find the bit your after I usually spend a while cross referencing on the net. Google the part and keep googling the numbers that come up, search these on eBay and in teh various suppliers sites. ALso use shop4 parts as a good starting point. The people there are friendly and very helpful too. I can usuallu narrow things down but iys easier with cars than the vans and van based stuff. Fiat may tell you but more like a corkscrew than straight..... Good luck with your hunt. Try posting specific questions in teh relevant forum area for your vehicle. Lots of experience to make use of.