blue is right, and the worst culprit is aluminum on aluminum. this will seize more or less immediately. you are correct that ss and aluminum + salt more or less make a battery; anti-seize won't help much there....paint might.
You can use zinc-plated or nickel-plated steels against each other because the plating tends to act like a lubricant.
Here is the bar attached to the car. I was surprised how close the 19mm bar comes to the shifter counter-weight. You can kind of see it in a couple of the pictures. I'd be a little nervous about using a bar any larger than 25mm.