I think that an animal is a living thing, with emotions and a personality, a car is just an inn animated object. I hope I'm never in this situation (right now I don't have a pet or a car...) but I did spend a lot of money for cat surgery once. The cat was basically found in the street, the money could have bought me about 200 cats in the animal shelter. It's not about money value it's about love and connection.
I think that a pet becomes a part of your family, anyone who doesn't see that and willing to take responsibility (financially and emotionally) shouldn't have a pet.