Theory predicts that laminar flow is easily triggered to turbulent. Once we go to 3D bodies with a proverse pressure gradient, the flow is much less sensitive and we can get extensive laminar flow.

Looking at wind-tunnel and tow tests from Carmichael, Raspet etc, on an axisymmetrical body the flow is still easily triggered to turbulent, save on the extreme nose. Even a small fly would cause a turbulent wedge.

Now, most wind tunnels have higher levels of turbulence as the atmosphere, so it could very well be that it isn't that bad in reality. Unfortunately, I haven't been able to find any actual testing in flight to determine whether the flow over the canopy and the canopy seam was completely laminar, completely turbulent or something in between.

Obviously, cockpit pressure is a big factor; overpressure most certainly will result in turbulent wedges. Still, does a Mandl (sic?) extractor and a cockpit with mild underpressure result in completely laminar flow over the front fuselage and the canopy?