Cars would get blown up when hitting a mine, but not by guys with grenades and rocket launchers.
The problem was that the country was lawless, it was really lawless in the true sense of the word. No one of the young generation had a driving license. 80% of the cars on the road had no license plates. That was because the cars was stolen. On top of that you can add all those who stole a car but didn't bother taking off the license plates, because there was no police. It was us, the international troops that enforced the law, and we could not possibly arrest every lawbreaker. We had more than enough keeping the civilians from killing eachother.
Fill the roads with young people with no proper training whatsoever, and with stolen cars. You don't want to drive on those roads, and if you have to, you wanna have the biggest vehicle so that you don't end up in a crunched piece of metal mess.