+1 for Mitsu's wish list, and +1 for RTHolmes wish regarding the engine sound location relative to pilot's head direction.

Even tho I know it might interfere with the direction other aircrafts are coming from..? Or is it?!
Just feels weird to have an engine "inside" your head..

The engine damage sound could be a metallic sound increasing in intensity as the oil dried engine runs hotter, and rpm should drop a tad just before the pistons finally jams to a full stop.
And might I add one more little sound wish? An engine stutter just before you run out of fuel also... ?
