So I had an idea. I thought maybe I could pretend to be intoxicated (or really relaxed) while driving. It actually works for me.
My approach is to give in to the anxiety and let it try to take over. I tell myself that I just don't care what it does to my body. As I'm in a situation where the anxiety is about to come I relax into it even more. The more the panic feeling wants to come over me the more I give in and say, "take me I just don't care anymore.” I stay calm and cool. If you fight it you're allowing it to exist, giving it credibility as though it is really something that can hurt you...if you give in, you tell yourself that it's a made up thing that can't really do anything to you.
On the freeway I used to sit up straight, turn the radio off, adjust the mirror (I'd just keep trying to distract myself from the fact that there were all these cars around me and I couldn't get away if I needed to). I would end up freaking out and drive dangerously in order to get over and pull off. Now I focus on letting every muscle in my body relax, I breathe slowly, I make sure I don't shift my head around too much. Picture someone sitting with their mouth open and drool coming out the side of one’s mouth. That’s how relaxed I try to get.
Get an attitude about you like, “I just don’t care what happens anymore.”