Define 'work'. ;-)
If you could get Garmin to flip the output image, and you mounted the Garmin face up under the glass, you'd get the image on the glass. but how visible it would be under various conditions would be highly variable, there'd actually be more info there than you want (sometimes blocking your view outside, and as others have said, the focus is wrong, requiring your eyes to refocus inside the cockpit to read it. If you're talking about a separate device to display the info, that's what GRT has done with the Hudly (post #23). It's not perfect; it doesn't focus at infinity like the megabuck military stuff, but it apparently does 'work'. I'd think that the biggest advantage could be during an IFR approach, because it would minimize required head movement, which reduces vertigo risk.