Some men behave as though their most cherished possession is their car. If he enjoys it, then let it be. If you watch car shows on TV, you'd notice that most of those attending it are men. It really has nothing with sharing. Men like to show off and if he thinks that his car is nicer and newer, he will use it.
Try to separate your feelings from the actual situation (be objective). Your interpretation of the event makes you feel a certain way. When you catch yourself feeling upset, figure out what is triggering it (is it really something that anyone else would become upset about, or is are there other issues) You'd have to be mindful and monitor your thoughts and redirect/change the as needed.