Car design is driven more by market analysis / price discrimination than engineering constraints. Engineering constraints explain some aspects of car design but they don't explain the generally conservative designs of a lot of automakers.
Take the new Toyota Prius, for example. The updated model almost looks like a concept car but still has a similar shape to other cars. There's no constraint reason Toyota couldn't have styled the car similarly in previous generations. I'm guessing they made the car look like this because Prius sales were falling and they decided they needed to be aggressive with styling for sales. They may have also decided that consumers that want a car with lots of cargo space are going for SUVs and crossovers anyways, so they could make the new Prius sleeker.
There are also tons of examples of automakers intentionally reserving nicer looking features as more expensive options or for more expensive luxury models. Fabric is not really cheaper than fake leather (both of these materials are just plastic). But automakers always charge more for fake leather.
Take the new Toyota Prius, for example. The updated model almost looks like a concept car but still has a similar shape to other cars. There's no constraint reason Toyota couldn't have styled the car similarly in previous generations. I'm guessing they made the car look like this because Prius sales were falling and they decided they needed to be aggressive with styling for sales. They may have also decided that consumers that want a car with lots of cargo space are going for SUVs and crossovers anyways, so they could make the new Prius sleeker.
There are also tons of examples of automakers intentionally reserving nicer looking features as more expensive options or for more expensive luxury models. Fabric is not really cheaper than fake leather (both of these materials are just plastic). But automakers always charge more for fake leather.