Break the sunroof glass and get into the car.
Try to pry open the sunroof.
You lower yourself on all fours and slowly crawl towards the sunroof. The sound of the roof creaking is not loud, but it seems like it could trigger the creatures at an instant. You get to the sunroof after what seems like an eternity and see that it is closed. You determine there are two options, you can break the glass can be opened with enough force.