It does sound like you are setting yourself up as judge and jury about this man and his motives; you say you can't talk to him directly about your perceptions because he would deny them but that your perceptions are yours alone, you do not seem to recognize; you have to speak directly to him to ever be able to get any idea of whether what you perceive is actually a problem or if you are "obsessed" with what he is doing, as Kathy points out.

Instead of playing umbrella games and trying to get back at him for behavior you perceive and think means something, you have to be more direct. You have to ask him why he made room and told everyone else about the car pooling but didn't think of and include you instead of just thinking he has other motives and being breezy about it, saying to let you know if someone drops out. It sounds like you are enjoying a bit of intrigue and the feeling something is "going on" between you and him. Find out instead of keeping it all in your head where you can "control" your perception, whether it is true or not.