Hence the $ in billion. Litigation would be a nightmare as soon as someone hacked your prius, but if security was an issue, they could tie it in with SKS, MD5 checksum the image, incorporate a sessionID with PriusUpdate that is embedded in the FW image sent over BT and add a biometric recon sensor to the MFD (since it's touch sensitive there are a few that come to mind).
I'm sure it will never happen for resons other than technical. Main one is test cycles. If everyone can easily update thier Prius, then there will be more frequent SW revs, which will lead to more introduced bugs, which will lead to more SW revs.....
I think there are even bigger $$ in the billion than any of these though. I don't think that toyota wants anybody to be able to peak at thier FW images. If so, reverse engineering would ensue. No matter what type of encryption they put on it. Last I heard any crypt could be decoded by a good farm of zombie boxes in about 12 months. Plus, why let customers do something, when the dealer can charge for it and make $$.
Still gotta admit, would be kinda cool to flash your prius
