yes, you ll need an international insurance card (zelena carta) and you should also check with the company insurance if there is a limit in how many days you can stay abroad (3,6 month...)
this zelena carta cost me 47.5 LEVA (EU + SCG, BiH, HR)
Thanks jeremi, my car as no insurance at the moment i was hoping to insure it online with a bulgarian company then drive over, where do i get a zelina carta from cheer's.