Soldato
And the car analogy does not work either. Manufacturers all now know how to make air con and power steering already and can in fact buy the systems off the shelf almost. Software on the other hand has to be custom written from scratch each time. Imagine if Bioware used Blizzards graphics routines or network code?
Companies don't write code from scratch these days at all! There's a whole industry around providing common code to games companies - netcode, physics, graphics engines, trees even.