I originally designed this to work with the Gen 1 iPad in it's case, but it ended up a little too tight, so I added some adhesive foam weather stripping and took the iPad out of it's case. I drilled four small holes and mounted this to the back of the headrest in my car for my son to watch movies.
Along with the SolidWorks files, the Zip archive includes a DWG with the flat pattern I used, and a sketch of the wood form I built to bend the acrylic sheet around. It also includes a PDF of the acrylic sheet I ordered from McMaster (#8505K812). The STEP file is only the holder itself.
With the foam this ended up fitting both the original iPad and the iPad 2.
The angled piece at the left edge is a reflector for the speakers, so it's louder in the back seat and quieter for the driver.