Robert, I have OP (Open Pilot) in my 4th Gen Prius Prime and have been running it now for 30K miles of actual OP driving. I am not an expert.... but I believe that OP requires the vehicle to have some sort of LKA, lane keep assist also known by other names, which requires a forward facing camera. Secondly it needs the adaptive cruise control, radar. I am not aware of any of the Gen #3 Prius's that have all this hardware. Upgrade to a Gen#4 and enjoy some of the new benefits. I drove my Gen #3 and loved it for ~280K miles before moving up to a Gen #4 Prime. Hope this helps.
Gen #3 Five with the technology package has both adaptive cruise control and LKA (and obviously front facing cameras). I love the ACC. LKA is pretty useless.
Check here but it says my '15 is not supported. Doesn't even ask the trim level so I don't think any of them would work. comma – Supported Cars
