There's been much agreement and disagreement in this thread, but it all seems rooted in one major aspect of the next model -- motor -- with weight being the other repeatedly raised aspect.
Unless BMW has changed it way of doing business in the last few years, money and costs still decide what models will be built and for how many customers that have what type of automobilistic tastes and preferences. So, from the outside attempting to peer in, there isn't much hope of glimpsing what is actually going among the players that ultimately decide which of what is included in the next model. However, rather than "What is possible?", perhaps a "What isn't possible?", as in "cost ineffective/prohibitive", or "What is permissible due to this that and the other?" may be a another way to spend time.
What we think we know.
All but certain differences from E92 model
- Improved straight line and handling performance
- Improved fuel efficiency
- Improved emissions
- Launch in Europe (2nd half 2013)
- Arrives in USA first half of 2014
We are likely to all agree that the next M3 will improve in the above three areas.
The following "unknowns" are so in the sense that we do not know how each interplays with the others nor do we have any real idea as to the extent any will influence decision-making by M design team, neither do we know what guidance the BMW/ M management has offered to the design team, and we certainly have no idea as to preferences of any individual members of the design team (They don't hold press conferences nor hold court in Internet forums/chat rooms.) nor the overarching financial philosophy of management that will financially enable or limit the boundaries of the model.
- Additional per unit cost to reduce weight by lb or kg
- The extent that the law of diminishing marginal returns factors into unit production cost where weight reducing parts are incorporated to the model.
- Additional per unit cost to develop blank sheet motor.
- Marginal savings per unit by foregoing a blank sheet motor development plan in favor of modifying existing N-type motor.
- Total generation unit sales target.
Additional limiting or compelling factors
- Other BMW/M model price points
- M3 price range
- BMW M5 performance
- BMW 1M role i.e Is it envisioned to be a model that BMW wants 1M owners to see as logically leading them to the “next step” M3?
- Market competition: What is the fifth generation M3’s competition?
- What are to be the distinguishing aspects of the M3 that make it compelling versus targeted competition?
*** If there is someone out there with insider status that could address the unknowns, please know that many of us here would greatly appreciate you doing so.