Here's what happens when you hit an adult Kangaroo that's in mid-air.That's a dead roo in the back-seat after going through the windshield. The driver's seat is on the right-hand side in Aus, so you can see here that this roo totally ripped the passenger side headrest clean off and bent the seat back on the way through.
Luckliy there was no passenger at the time and the driver survived. He was also lucky that the roo died on impact or it could well have disemboweled him trying to get out of the car.
NSW Ambulance said at least 83 car crashes resulting in injuries had involved kangaroos so far this year and warned of an expected sharp rise in that number over winter. SOURCE