[Frostquack]

Asus P7P55D Deluxe: The Mugen 2 generally fits and works.

Only problem is the placement of the fan.
• You can't place it on the right side (seen from the side when the back if the case is at the left; that way that the Airflow targets the rear of the case) because it collides with the RAM
• If you place at the bottom (also seen from the side) this works only when you haven't occupied the blue x16 PCIe-Slot (which is the fastest slot). If you have an old graphics card that is satisfied with x8 you can use the lower, grey slot and leave the fan at the bottom

So if you want to use a fast graphics card the only way is to mount the fan turned around (sucking the air instead of blowing) on the left, between cooler and rear of the case which sadly is often only some centimeters away from the rear case fan. Not the optimum placement but should work.

(Edit: beats me, now this works. I'm using Corsair RAM without big heatspreaders and the fan is mounted on the right side blowing to the rear. A simple graphics card is mounted into the blue slot, fits. If a bigger graphics card also fits in there, I'm perfectly happy )