Auto Union V16 Streamline Special
Aside from being ridiculously fast even today, let alone almost 70 years ago, this is believed to be the first race car with significant aerodynamic engineering applied to its development. Many of you will recognize it as a prize car in GT4.
That's how I know about it too.
http://www.ddavid.com/formula1/auto_c.htm
http://prnewswire.com/cgi-bin/storie.../379955&EDATE=