People that make comments like this typically have no concept of how automotive engineering works or how long it takes to design cars on existing platforms, let alone new technologies and architectures. GM, Daimler, Chrysler, and BMW have had a joint R & D centre set up for a LONG time now in Troy, Michigan where they have been developing hybrids. While Honda and Toyota may have beat them to market on a couple models, nobody is as pervasive as the Detroit Three when it comes to the variety of hybrid vehicles offered today, and they're just getting started. Looking at the average lead time to get a vehicle on the road, can you imagine the cars we'll have in ten years now that Detroit is even more desperate now than they were in 2000 for a green image makeover?
Your comment that "it took near bankruptcy" for GM to switch to green technology is patently false, though. This transition has been going on for longer than you'd imagine - since before "Who Killed The Electric Car", since way before the Iraq war and the subsequent spike in gas prices, and since way way before these recent auto industry troubles. Engineering doesn't happen overnight. These are still some of the biggest organizations in the world, and with good reason - with pooled resources they are even more efficient than they would be as hundreds of small outfits. That said, while they are more agile than they have ever been, being agile in automotive means taking a few years to do something new rather than a couple decades. If you can do better, I invite you to become a Henry Ford - start your own auto company and see how difficult it is. Tesla has been experiencing this firsthand - automotive is lightyears more difficult than they anticipated or expected.
Doom was originally developed on NextStep, which is the OS that was used as the basis for Mac OS X when jobs came back to Apple in the late 90's. The iPhone runs OS X!
As a result, the DOS version and every other version of Doom are ports. The iPhone version is essentially on its native, original platform, probably utilizing the original code with some tweaks for the touch controls, etc.