The canopy has a hitbox that can certainly be intentionally shot, if one knows where to aim, but the location is not on the subtarget list.
Lifesupport is a different module, but is often placed immediately behind the canopy, so targeting it while an opponent is facing you will tend to put shots through the canopy area on many ships, especially if you fire from slightly below.
Sensors are similar. They used to be targetable, but since they are in an exposed location (usually in the nose directly infront of the canopy, or just below it, it was a quick way to ensure the eventual destruction of enemy CMDRs in the days before there was a reboot/repair option, so it was removed from the subtarget list in 1.2, IIRC. You can still destroy them though...it's just rather pointless in the current game.
