A GMI original story, apparently:
Initially Alpha was going to be a four-cylinder only chassis for small premium cars, so naturally development focused on optimizing the Alpha platform for four-cylinder mills in a very light package. Well, Cadillac’s first condition was that Alpha be re-engineered to package a naturally aspirated V-6 engine – and that was non-negotiable. This about-face on engine selection would become the first of at least two engine requests that led to a re-engineering of the Alpha chassis to accommodate the new requirements. More changes (read: more mass and cost) were required for the addition of all-wheel drive.
What started out as a great handling, small RWD program, began it’s mission creep from being very focused to being all things to all people. And as it evolved, certain “hard-points” from previous development were locked in, even though the base program had transformed itself. For example, Alpha was designed with a very sophisticated multi-link front suspension with near perfect geometry for the car as it was developed at that point. That geometry was “locked in”. As the car grew and became heavier with more features and content, that original geometry was no longer optimal. Our sources tell us that GM is now attempting to mask this sub-optimal geometry with chassis tuning rather than doing the right thing and actually fix it.
According to sources familiar with the Alpha program both internally at GM and the supplier level, GM has made several other additions to the requirement list of Alpha beyond engines. Among the additions were: a new electronics system and aerodynamic shutters (similar to the Volt).
Each addition has caused another issue to engineer around, thus causing the Alpha program to exceed GM’s mass requirements for the car by nearly 500-pounds. It is unclear how heavy Alpha products will be, but every independent Alpha source GMI has communicated with has indicated that the final curb weight could push 4,000-pounds unless GM puts the program on a mass reduction plan before launch.
Source
Alpha reportedly cost $1 billion. Reminds you of what got GM into bankruptcy in the first place doesn't it?