Shooting from vehicle... As driver?

I'm fairly new to H1Z1, but I just got destroyed by what I thought at first was a group in my last BR. Jeep was driving at me from behind a tree, then a shotgun went off beside me. Figured the driver/passenger jumped out, but when I dodged the car and went around, there was no-one there. Car came at me for another pass and shotgun blasts start going off. Hits me, I go down. Figure he had a passenger, but there's nobody in the jeep but one guy. Is this something that's known? Can you jump back and forth between driver/passenger seats to shoot at people or is this just an exploit?