Then how come TVR can make a 400+ hp NA inline 6? We also have these cool new things called turbochargers LOL No one said it had to be NA. BMW came around on the 335 (although I think the 335 is underpowered stock for a modern turbo engine, its got decent potential from what Ive seen.) I dont think BMW is pushing it that far yet. Porsche makes 400 from the NA GT3...yes, its not an inline, but the inline has just as much or more potential for power.Yep, BMW has pushed their inline 6's as far as the can go (reliably speaking for the domestic market).
The V8 was the most logical choice with all the new high powered/re-engineered opposition from Audi, Cadillac, Porsche, Jaguar, Mercedes Benz alike.