It is a big deal for seveal reasons, the biggest is that in the 1960s, pillarless cars were more desirable due to the cleaner look with the windows down (that includes perofrmance models like the Road Runner and Super Bee). That's just the way it is, but there was also a time when you couldn't give away a Barracuda coupe as the fastbacks were considerably more desirable. It doesn't matter what ONE person likes better, it's about how many will be interested. I've been around this hobby since the late 70s and I wouldn't consider a sedan for a build. Yes, it may be an old bias, but I'm not the only one (actually, I'm to the point where I wouldn't consider something with a permanent roof...).