This happened to a friend of mine in his van... Worst mess I’ve ever seen in a car is “shitbarf”. His dog came camping with us, found a friend’s untidy latrine pit (fill your holes after you use ‘em, people), consumed all the contents. Pup hopped in the van for the drive home and shortly thereafter barfed up about a gallon of liquid human feces all over the van. Saw them at the trip destination and they were shattered people.