I bought this car because it was so fun to drive and makes me smile every time I get in it. I've found that shifting manually lends to a smoother ride than automatic mode. I've driven the car on highways at 70+ mph speeds with and without tractor trailers and the drafts following the tractor trailers does create an environment that pushes the little car around, but honestly, even my Murano gets pushed around when traveling behind tractor trailers at high speeds. A majority of the driving I intend to use this car for doesn't involve highways anyway so I feel very safe and comfortable.
The convertible top, of course. It is just so fun to drive. The fuel efficiency is awesome too. It handles great and the compact size is a real plus too. The automatic top is awesome. The real bonus is the ability to change the color of the car by switching out the panels.
Like the other reviewers, a smoother CVT would be nice. The Leather seats are not as comfortable as the the cloth seat. A Tilt wheel would also be a nice standard feature.