Wheels, my friend, wheels...can make or break the look of a lot of cars, for SURE. And that's exactly the case here. Even barring the slight fascia differences, put a set of the GT wheels & tires on a base...and wa-la...it's transformed.
Very common thing, especially when base vs. higher end is compared, on a variety of vehicles.
As my father's adage goes..."Wheels alone can make or break a car", hah
Buick of the 90's, 00's, etc. in particular just drove him nuts...think back to the different HORRIBLE wheel choices on a LeSabre, for instance. Ugh. Not a stunning vehicle itself, but change the wheels and wow...
I really like the new Vibe, too, oddly enough...even in "the one one had a reaction and got puffy" form. At least even in that base form, it still looks better than the Matrix base...with even worse hubcaps and a really squashed fish look.
^^Well, these don't look that bad...but in person, it's really an odd bugger, and a squashed one at that.
The wheel thing is big on the Toyota too...but the overall shape is also even more of a blob, and lacks the key sharp details on the Pontiac that make it more appealing.