Serbian (and other Balkan) green card insurance is more complicated than most realize. Here's the situation based on actual experience June 2010.
1.
Vehicles registered in most EU countries (e.g. Germany), and therefore insured domestically in those countries, 'automatically' include green card coverage for non-EU Balkan countries Croatia (HR), Bosnia (BiH), Serbia & Montenegro (SRB or SCG), Albania (AL), Macedonia (MK), etc.
2.
Vehicles registered in the UK, and therefore insured by a UK underwriter,
may--or may not--include Balkan coverage, depending on corporate policy of the specific UK underwriter. UK vehicle owners may be able to get that Balkan coverage for an extra fee from their UK underwriter/ broker, if it's not included in your regular policy.
3.
Vehicles registered outside the EU and UK (US, Canada, AUS, etc) must of course buy a separate Green Card policy for vehicle use in Europe. Whether that separate Green Card policy includes the non-EU Balkans
depends on the separate underwriter (source) of the policy:
3.1. Green Card policies brokered/ sold by
Motorcycle Express - Ship Your Bike in North America
and
TourInsure - the specialist for international automobile insurance in Europe
are both underwritten by AXA, and
include non-EU Balkan countries,
but the monthly premiums are more expensive than
3.2 Green Card policies brokered/ sold by Mototouring,
How does the European Green Card Insurance work? in Milano
are underwritten by several Italian companies, and do
NOT include non-EU Balkan countries;
3.3 Green Card policies brokered/ sold by Knopf
Green Card in Germany
or any office of the German auto club,
ADAC - Ihr Partner in allen Fragen rund um die Mobilität. (Allgemeiner Deutscher Automobil-Club)
are underwritten by
www.arisa-assur.com, and do
NOT currently include non-EU Balkan countries.
If you buy a separate Green Card from Mototouring, Knopf, ADAC, or direct from Arisa, your Green Card will show the non-EU Balkan countries, including Serbia, "blocked out." In theory, that means that you
must and can buy separate vehicle Green Card coverage crossing the borders into each Balkan country.
Here's where it gets (even) more complicated.
Based on actual border crossings in June 2010, using ADAC/ Arisa Green Card on US-registered bike
Leaving Slovenia, entering Croatia (HR), at small border crossing Metlika, there was no vehicle paper check, therefore no separate HR Green Card was required, but also there was no border facility/ broker to buy HR Green Card if you wanted it; experience at that small border crossing may not be the same as at the major A2 motorway crossing between Ljubljana-Zagreb.
Leaving Croatia, entering Bosnia (BiH), at major border crossing, E71 between Dubrovnik-Mostar, there was no vehicle paper check, therefore no separate BiH Green Card was required, but also there was no border facility/ broker to buy BiH Green Card if you wanted it.
Leaving Bosnia, entering Serbia (SRB or SCG), at one major border crossing, E761 between Sarajevo-Belgrade, Serb Customs denied entry of vehicle into Serbia without separately-purchased Serb Green Card, BUT Serb Green Card was not available for sale at that crossing. Serb Customs directed us to closest smaller border crossing 30 km south, where Serb Green Card was purchased--after calling private broker to come to border station--for
minimum one month = 60 Euros.
Note that it's possible--unknown--that Serb Green Card can be purchased at other major BiH-SCG crossings, Rte 19, or the A3 motorway between Zagreb-Belgrade.
Bottomline--if your non-EU Green Card is from Mototouring, Knopf, ADAC, Arisa, etc. you'll very likely have to pay an extra 60 Euros to enter/ drive through Serbia. That may still be cheaper than the higher premium charged by AXA-underwritten non-EU Green Cards (that include Serbia), but you also have to consider the extra hassle/ time lost in Serb border crossing purchase.
All that begs a separate question: if Croatia and Bosnia are not covered by a particular underwriter's Green Card, and you're "supposed" to get it at the border, BUT it's not available at the border, how do you get it, and what happens if you're libel for a 3rd party injury/ accident in those countries ?