I've not driven a coupe but have driven a sportsroof and vert versions. Don't know about the head height but the rear visibility is a lot better on a coupe and vert.
There are many (left hand drive) Mach 1s out there with right rear quarter panels that have been damaged from lane changes where the other car could not be easily seen. When looking in the rear view mirror you only have a 3 or 4 inch slit of rear visibility due to the 15 degree angle of the rear glass. Here's an experiment for you...hold your hand out in front of you so you're looking at all of your palm. Notice how wide your hand is. Now rotate your hand almost 90 degrees so your thumb is toward you. Notice how narrow your hand is. This is kind of what the rear glass on a sportsroof does.
The plus side of this is the spirtsroof shape makes the car allway look like it is going 100mph even when hust sitting there.
