This thing working from factory is probably the only one that works, after market solutions whithout holographic pad (very very expensive) are not working in every light conditions but anyway this is fun to have.
FYI a HUD without holographic patch requires that your windshield has some Butacite (from Dupont de Nemours) in it or as suggested is dark tinted.
have a look at this...
So this Butacite is probably the only thing that can cancel the image spreading in two or more echos.
Now against the sun, there's no other solution apart having a brighter light source which is nearly impossible to have but there's still a way to try to getting better image
hope this helps...