A.R.
M., Sometimes the jealousy increases at this age when the younger sibling comes into his own. Maybe it would help if you could read to your older son alone at night while your husband reads to the younger one. He may just need a little more one-on-one time.
I would not let him dictate getting in the car seat first and all of those things. Let him know he is not in charge of all of that. That will set up more rivalry because the younger one is only go for that for a limited time then they will beoth be fighting so you make the rules about that stuff. But a little extra alone time with you may diminish the other things.
You don't have much control over making them close but you can do things that don't prevent it. I would never compare them. I used to try to prasie each of my kids in private rather than in front of the other. Praise them when they are playing well together, "You guys are so good at sharing with each other" etc. My sons were not very close when they were young but as they have grown (23 and 26) they became close on their own. It is a great joy to me. But they are unique people and sometimes siblings are close and sometimes they are not. It is too early to judge for yours. Plus they go in and out of phases as they grow.
I had a friend that had two sons and she always bought one of their Christmas presents that was to share and required them working together. I thought that was a great idea. I remember one year she bought them the large lego electric train and they loved it.
Good luck. Have you read the book SIBLING RIVALRY (can't remember the author, old but good advice--get it on e-bay)
A.