Ok you're describing the exact kind of irritability that comes along with being in a long term relationship and being around the same person way too much. The little things they do start to really bother you. Its hard to deal with because they're little things in and of themselves but they add up to something that you can't ignore. Everyone has experienced this at some point their lives, whether its spouses or parents or siblings or kids or even friends...
But if you're going to act like a dick to your wife in the car, you need to just not ever ride in the car with her, if at all possible and explain to her simply that the way she acts in the car makes you annoyed and you'd just rather not ride with her. I had a similar situation with my mom-- I absolutely hate riding in the car with her, either with her driving or me driving. I take measures to avoid it at all costs, and I even tell her that I'd just rather not. Don't wait til its actually happening, because then you'll just get angry all over again-- explain it beforehand, when you're not angry, to set your boundaries. Sometimes we just can't tolerate the things other people do-- and you just have to figure out how to avoid the situation-- without necessarily avoiding the person altogether. You have to figure out how your emotions work. If you know ahead of time that you're going to act like a dick and not be able to stop yourself, and if you really would rather not act like a dick towards your wife (which I'm assuming is the case), then take action to remove yourself from those situations which you know will set you off. Don't just simmer and try to tolerate it, or say obnoxious things like how you described.
But if you're going to act like a dick to your wife in the car, you need to just not ever ride in the car with her, if at all possible and explain to her simply that the way she acts in the car makes you annoyed and you'd just rather not ride with her. I had a similar situation with my mom-- I absolutely hate riding in the car with her, either with her driving or me driving. I take measures to avoid it at all costs, and I even tell her that I'd just rather not. Don't wait til its actually happening, because then you'll just get angry all over again-- explain it beforehand, when you're not angry, to set your boundaries. Sometimes we just can't tolerate the things other people do-- and you just have to figure out how to avoid the situation-- without necessarily avoiding the person altogether. You have to figure out how your emotions work. If you know ahead of time that you're going to act like a dick and not be able to stop yourself, and if you really would rather not act like a dick towards your wife (which I'm assuming is the case), then take action to remove yourself from those situations which you know will set you off. Don't just simmer and try to tolerate it, or say obnoxious things like how you described.