Not a slogan per se, but it was in one of Cadillac's adverts. "When you turn your car on, does it return the favor?"

Kia is dead on with theirs. "The Power to Surprise."

I like the confidence Porsche has. "Porsche: There is No Substitute."

Saturn has one of my favorites because it works on two different levels. "Saturn: Like always, like never before."