ADHD & aggressive driving

I need advice. My boyfriend gets very aggressive and angry when he feels that another driver has "wronged" him, and it scares me. Every time it happens, we argue because he doesn't get that he's putting people at risk. 

I'm tired of arguing with him about it. I've told him that it scares me, puts me at risk, dangers my life, we don't know what the other drivier is capable of, theres always 2 ways to handle a situation and he chooses the dangerous way, he's not teaching anyone a lesson by getting back at them, he needs to control his anger, what if I was pregnant, what if there was an accident, you can drive however you want when you're alone but you can't drive this way with me in the car, is this how you carry precious cargo, etc....

I've tried every line I could think of and I've said them all humorously, seriously, and then angrily. The only thing he'll apologize for is that I thought my life was at risk ("but you're the only one that felt that way"...his words). So, it happens again...and we argue again...

So does anyone have any advice as to how to talk to someone with ADHD about their aggressive driving? Any other tactics I could try??