While the convertible hasn't been released yet there are a handful on US roads as we speak. Here's an email from a reader who encountered one:

Heads' Up on the new new Mini Cabrio!!! I live in Schaumburg and was driving home from work on Roselle Rd yesterday. I saw a new BRG Mini Cabrio w/the roof down and Cordoba Beige interior!!! I didn't think these were going to get to the dealer until later in the summer.

We were driving in opposite directions (in traffic of course) so I didn't get a close-up of it. However I did honk and got an
acknowledging “wave” from the driver. It was definitely a dealer
demo car (had the dealer plates on it and the driver looked like a car salesman i.e. – decked out in white shirt and tie)

Happy Motoring…..
Chris

I believe I know who that was actually as there's a BMW Corporate facility in Schaumburg. In fact that will probably be the car that will be making the rounds making the rounds at the local Chicago dealers later this month and in July.