Making of Gary Numan DieHard commercial

Syyn Labs, the folks who created the Rube Goldberg machine for OK Go's "This Too Shall Pass" video, recently did a commercial for DieHard featuring Gary Numan performing his classic song "Cars" on actual cars (their tuned horns), playing them like a piano, all powered by a single DieHard battery. We were intrigued and asked them to tell us how they did it. They sent us this behind the scenes video. The commercial is here: http://www.youtube.com/watch?v=s4YsMVA8DoU