He's the reason I'm the dumb/sane one in the house.
No, I definitely wasn't attributing his total jerkishness to that. My entire family, including me, are all heavily on the autism spectrum, verging on Aspergers. My brother is just the only one formally diagnosed, and I am disdainful enough of self-diagnosers that I wont say anything else about the rest of us unless I'm sure.
No, because then I would be harming my brother.
I don't want him to feel unwelcome here. Also, I love him. I never want to anger the people I love. I might contrarily feel the urge to really irritate the crap out of him for being unreasonable, but I hate having anyone be mad at me if I care about them.
Also, he's kinda scary when he's mad, and I don't want him to lash out at my parents.
Also, the car thing is second-hand, my dad told me about that, I wouldn't know the precise details, so I can't give any explanations for that. I just know it was bad enough my dad was ready to let him get his own way home.