Don't have any particularly good story. They are just really good at understanding and fixing anything mechanical using the most basic of tools. I actually think that the type of brain that makes you good at programming is similar to being a good mechanic.

Yep. I've found that my troubleshooting methodology and being able to break down complex systems is equally transferable in between software and mechanics. I think that systems and software people are the "modern" mechanics of the world. It explains a lot as to why my father and grandfather were both mechanics and tradesmen, and I'm now a systems guy.

Absolutely, trouble shooting requires abstract thought and following long logical chains as to why something is failing. Cars are complex systems just like software can be, good knowledge of many different domains inside your main discipline is required to put the pieces together. I have always found good mechanics to be really switched on individuals.