Corporations have adopted risk management strategies for dealing with latent defects. You can be certain that Porsche management crunched the numbers (or someone did it for them) to determine whether re-engineering/re-tooling M96 would be cost effective, or whether responding to problems as they arise "in the field" would be more economical. An additional factor that likely contributed to their current policy is decliing length of average ownership since the manufacturer obligation declines with subsequent owners over time. The proliferation of leases and financing plans that encourage short term ownership maximize profit and decreases long term obligations to initial (and repeat) customers. This is particularly true of the US market.