HUD Display where to buy

Hi People...

At first, the question who I am... =)
I did an Apprentice as Automation Technician, and work now as something 
like an IT-Ingenieur... (planning Network Monitoring Systems and things 
like this...)

My Project:
Put a Raspberry PI into my car.

Input a trackpad (integrated next to gear selector for easy handling)... 
and maybe a litle Keyboard (placed somewhere other... )
Output 3,5mm for Audio and HDMI, VGA, or DVI for a HUD.

Now the questions...

Does somebody now a serious company or store where I could buy a not 
very expensive HUD, where i could project a normal display like windows 
on my car- Frontwindow?

Is a HUD like this already existing?

Thanks for answers...