NHTSA Complaint #11600626 — 2008 TOYOTA PRIUS

In temperatures above 95 degrees the vehicle shifts into neutral while driving, and you need to physically hold the shift lever in Drive or Reverse to keep it out of neutral. It won't go into park at all unless you restart. This could cause a fatal accident while driving, particularly on the freeway. It has not yet been confirmed since it only happens at very high temperatures, which is rare where I live (Seattle). There has been quite a lot of discussion on Reddit and other internet sites about this problem with Priuses, particularly the 2008 model. I have an appointment with my mechanic to replace the shift lever assembly, which appears to be the most commonly referenced fix. There are no warning lights, other messages, or symptoms before or while this is happening. The problem resolves when the air temperature goes back down.