Yeah stick your head out the window at 300 km/h, that will be fun.

There's one guy I see often in a 109 that jettisons his canopy after take off.:(
It would be a good idea to have ground control update locations of enemy aircraft at your request.

what it needs is a performance disadvantage to have it open as it stands now there isnt one

Agreed, hopefully with the next patch we will get open canopy sounds that will annoy ppl so much that they are forced to keep the canopy closed.

But like welshman said in the end we should have a heft speed penalty for an open window.

Yes, definitely there should be drag and I wouldn't do it during combat anyway. Could still be useful for reconnaissance. And your head isn't actually 'out' of the cockpit...