I heard a tale about one hitting the side of a vehicle and ending up in the back seat, badly injured but still alive and kicking. A similar thing happened to a mate of mine. He was driving a HJ-45 on a property, so not going fast. He turned his head toward his mate in the passenger seat as they were talking, just as a big roo smashed into the driver's side door. On hearing the crash, he instinctively turned his head back and the roo's head and shoulders were protruding into the window and he was face to face with the roo with only couple of inches separating them. It was only for a split second till the roo's head and shoulders recoiled back out of the vehicle. It traumatised him a bit I think.
A bit of a coincidence but some time after that, the same mate that had the roo come in his window was in the pasenger seat and I was driving. Very similar story, I was talking to him and unfortunately had my mouth open when a long, springy mulga root flicked up off the front wheel, hit the door with a loud bang and threw about half a shovelful of red dirt in my face. Because I was talking at the time, the mouth was full of red dirt as well. The mate thought it was funny but I wasn't overly amused. At least it wasn't a roo.