But nobody would buy it. After all, the Prius is very similar in shape (just smaller) to perhaps the most unfashionable car of the decade, the Pontiac Aztek (introduced in 2001, now discontinued). The picture above is of an Aztek, not a Prius.
Conversely, nobody gets very excited over the Honda Civic Hybrid, because it doesn't look like you're saving the world by driving it. It just looks like you're some loser who can only afford a Civic. In contrast, when you are driving a Prius, everybody can instantly recognize it's a hybrid.
Basically, people choose cars to advertise themselves on the mating market. That's fine, I've got no problem with that ... except for the tens of millions of car-buyers who aren't supposed to be on the mating market because they're already married. Consider all the soccer moms who refused to buy aerodynamic minivans because they're too mom-shaped. Instead, they bought squared-off SUVs, which get much worse mileage than minivans of similar capacity, because they felt they made them look sexier.
So, you have to give Toyota a lot of credit for figuring out how to trick us knuckleheaded Americans into wanting to eat our vegetables.