Police are investigating who kicked one of the car's doors in.
The incident occurred several hours after the vice president of the Slovene parliament, Marko Pavliha, publicly called on the government to change its tactic towards Croatia.
In the wake of an exchange of diplomatic notes between Ljubljana and Zagreb after Croatia granted concessions to its oil company INA to drill for oil and gas in the northern Adriatic, Pavliha urged the government to cancel a scheduled session between the two countries' governments and to consider recalling the ambassador in Zagreb for consultations and calling on Slovene citizens not to visit Croatia.
Pavliha's statement was supported only by the president of the Slovene National Party, Zmago Jelincic.
Pavliha's colleague Jozef Skolc compared the idea to discourage Slovenes from vacationing in Croatia with the embargo on Slovene exports to Serbia 20 years ago during the Slobodan Milosevic regime.