Acura is technically ``Honda of America''. It's Honda's ``luxury'' line (much like Infiniti is for Nissan and Lexus is for Toyota, not that I know those brands exist in Europe) but, other than the NSX, the models are not the same. I believe that the new Acura TSX is the same as the European Honda Accord, though. (And our Honda Accord is different.)

Basically, Americans probably wouldn't want to spend high-dollar amounts on a car that just said Honda, as it still has something of an econobox legacy, so they started a different brand that has a higher cachet.