3. 1969 Ford Mustang Boss 429 Rear Engine
The Boss 429 Rear Engine is one of the most interesting Mustang prototypes. Despite the fact it didn’t appear on the show circuit back in the late ’60s, it caused a lot of controversies. Basically, they took the 1969 Boss 429 and moved the engine to the trunk. Then Ford extensively tested it to see if this conversion had significant advantages over the standard layout. They placed the engine longitudinally in the trunk and connected it to the rear wheels over the C6 automatic transmission unit.
Next, they turned the rear glass into a hatchback door to provide access to the engine. In fact, the entire conversion was surprisingly trouble-free. The Boss 429 Rear Engine had a 40/60 weight balance. The added weight over the rear axle helped launch it off the line and reduced wheel spin. However, Ford realized there weren’t any significant performance improvements, so they decided to kill the project.