The point has been looked at from 1949315 angles and it really comes down to this :
It's been said. You're driving rental cars. They've been used and abused and then used again. Not to mention ALL rental companys buy the worst model car available. That 3.0L V6 should have more get-up to it? No...it's a Pontiac and it probably weighs more than my friends Ranger with his 3.0L V6 and that shits slow. Europeans demand better cars because you guys have better roads to use them on :P Here in America most people just want to get from point A to point B. Most people know nothing about cars, suspension, engines, throttle response etc etc. They don't care. They want to get where they're going and get there without it breaking. If it does that, it's a good car. We also have a LOT of emmission problems here making it hard for outside companys to bring their good cars here. Not to mention the fact that you're used to driving a $40k 330HP car back home, which gives you a huge bias on the subject. That's like me using a 4GHz computer and then switching to a 500MHz computer. Nothing will seem as good ever again.
Honestly, I know it's just your opinion and all, but you're definetly driving the wrong cars. Chevy Malibu...POS. Pontiac ANYTHING nowadays...POS. They're rental cars. They're econ cars. They work, they get you where you're going and they don't break on the way.
In response to all of you that say Americans are bad drivers... You're right to some extent. I've passed on the right plenty of times, for the simple reason that someone already stated. Stupid ass soccer moms that go 55/65 (speed limit) in the FAST LANE (left lane) on the freeway deserve to get passed. Most people here drive at least 80 on the freeway, if you're not going fast, if you're not gonna get outta my way, i'm going to pass your ass. It's not bad driving, it's the whole concept of GET THE FUCK OUTTA MY WAY YOU'RE GOING TOO SLOW FOR MY LIKING.
Americans in general suck at driving? Maybe. But we do have too god damned many people in this country.