I'd say it's mostly because of safety regulations, what with cars nowadays needing super strong crash proof frames, crush zones, all sorts of airbags and electronic nannies. These things take up space and weight.
It can also be contributed to the general consumers' demands for roomier and more spacious interiors, and just how much more technology and stuff we're cramming into cars.
It's all gotta go somewhere.
i was waiting on a moment, but the moment never came. all the billion other moments, were just slipping all away. i must have been tripping, we're just slipping all away. just ego tripping.