Absolutely LOVE the Q400 ... she laughs in the face of P3D4 Dynamic Lights, msaa vs ssaa, and doesn't matter if you fly her upside down, or shift all the sliders to the right, she refuses to drop one single FPS in the process. It was only the cockpit lighting that was not to my liking and so I've created some more realistic cockpit lighting with the help of FSLSpotLights.
Please read the README.txt - !!
Also included is the tweak to make the tiller work with rudders.ENJOY!!
FSLSpotLights.zip