I've been meaning to post this for a while now. After being tired of the stock "elbow rest" that Toyota provides, I used my Makerbot to print up a CAD of a different (longer, taller) attachment system, using the stock screw points. It's very solid, been on for over a year. Basically, it is an armest that when retracted is pretty much in the most extended stock position. But when extended, pushes it out another 4-5 inches, making it a true ARM rest. The trick was creating a system that would retain the sliding option (rather than fixed). The armrest opening button is also still very easy to get to (I press it from the side). Funnily, I'm actually selling my Prius C (bought a PiP), but wanted to get this out there in case anyone had any questions.
