As a semi related aside, when I was younger I thought that 4 door vehicles were insanely ugly compared to their 2 door counterparts. Now that Im older I think about being pinned in the rear of a 2 door car after being in an accident and I instantly feel claustrophobic. On the other hand, the fewer holes you put in a car, the more rigid the structure.

My first car was a two door Honda hatchback, made in 1992, and when you pulled off the plastic panel over one of the rear seat speakers, underneath the speaker bracket was simply the sheet metal of the body. Literally nothing more than a cookie sheet between you and the outside world.