Hi there!
I am Mihailo a.k.a Gibanitza from Serbia,Belgrade ...
These Pandas were imported from Italy ( don't know if Aca mentioned that) where they were used in Telecom Italia as utility vehicles. Year of production is mostly 2002 and there are some made in 2003, engine is 1.1 MPi (engine code 187A1000)... Body is ussualy in very good shape (despite numerous scratches and smaller dents), mileage can be rather high on most of the cars (around 60 000 miles), and bad news is that there is no opportunity to do test drive properly before buying it 'cause they are not registered and have no plates though you can pick up some mechanic who has diagnostic equipment to check up candidates.
Distance between Novi Sad and let's say London is about 1200 miles (passing through Hungary, Austria, Germany, Netherlands, Belgium, France).
In Serbia Cost of converting them to passenger vehicle is about 200-250€ for parts (rear hatch with glass, rear windows, rear seats and if you are lucky you can get parcel shelf

) and about 50-60€ for atest (homologisation?)...
Don't know how customs works but I think (not quite sure) that our goverment signed
Stabilisation and Association Agreement with EU so there are no customs fees any more... But I think that it is mandatory for used car to be registered if you want to export them (about 150€ for Fiat Panda)...
If you have any more questions I will be happy to give you hopefully usefull answers...
Regards,
Mihailo