LMFAO! Do you even know what a flat plane crank is? It doesn't sound like a 4 cylinder. It kind of sounds like two 4 bangers firing at once. Have you ever heard a Ferrari 458 Italia or a Lotus Esprit? That's what a flat plane would sound like, not the rice rocket noise you have in mind...
Car manufacturers make money off of stepping stones. Each year they may add a few updates but never everything they are capable of. For example the 2010 Mustang had new body and interior but carry over transmission and engine. If the 2015 mustang is 3300lbs with 500hp, DI and the 10 speed auto...
Cylinder deactivation is easiest in push-rod motors and motors with direct injection. If you want it then you have to wait till ford launches DI in the coyote motors...