While I'll be the first to admit that the ride system is amazing, the attraction itself is weak...and I'm not talking about it being "thrilling" or "extreme" enough. I don't care for it because, as others have mentioned, it's little more than the conditions you experience on your drive to work every day or for that matter, on your drive to EPCOT. Turn on the air conditioner, it's cold. Turn on the heat, it's hot. Slam on the brakes to avoid the person doing something moronic in front of you, go over bumps in the road, drive fast...none of these things are unique. They're utterly commonplace, which makes for a dull experience for me. Yes, you're in a tiny car doing these things, but that doesn't make it any more exciting for me.
Next, there's the complete lack of educational value. I don't feel I've learned a thing coming out of there, except that speed turns people on.
Then, there's no forward-thinking. Future World at its best not only inspires and stimulates the imagination (and Test Track doesn't do this for me, either), but it only tells you how cars were tested in 1995. Do they still test them the exact same way? Possibly. But there's not a hint of "the future of transportation" anywhere in the ride.
Finally, it's one of the least detailed dark rides ever. There are so many areas of nothing but black space, and the props they do use often look cheap and tacky - wooden cut-outs of trees, anyone?
To me, the spirit of Disney just isn't in this attraction. It has the look of shoddiness about it to me. Yes, many people do like it, and that's great for them. As for me, I consider it EPCOT's weakest link, moreso even than the current Journey Into Imagination with Figment.
Ultimately, I feel the Carsland attraction to be placed in California Adventure will make this ride system feel properly used. It looks as if they'll be telling some kind of story, and it's not set in a Park that I expect to have attractions to educate, inspire, and give me a positive outlook on the future.
On the other hand, I do enjoy Mission: Space, Expedition: Everest, and to a lesser degree, Dinosaur. Those I feel do live up to the Disney standard of excellence.