Little is known about this 3G-enabled MacBook Pro prototype, but we imagine one of the many reasons it didn't pass Apple's notorious muster is Steve Jobs probably blew a gasket at the aesthetics alone.
The laptop is a 2007 model complete with 3G hardware, bright red motherboard and a SIM card slot built in. Typically, Apple prototypes have red innards, in case that question comes up in your next Trivial Pursuit game.
The owner was able to get the laptop back to working order, sans the 3G connectivity, which the computer actually recognizes but cannot use.
Interestingly, the "solder footprint" for the 3G antenna and the SIM card location are still present on machines from that era. The owner speculates could be due to a last-minute decision to remove the functionality. Sounds about right. [MacRumors]