Hi,
I saw this today, and thought it might interest you guys.
Apparently, RinSpeed a Swiss car tuner has developed an aquatic car. You need to look at the photos and the video. Personally, I think it one of the coolest cars I have ever seen. If I had $400k to spend, I would buy one.
Enjoy!
http://www.usatoday.com/money/autos/2008-02-15-squba-car_N.htm?csp=34