One problem related to transmission not go into gear has been reported for the 2007 Toyota Prius. The most recently reported issues are listed below.
My 2007 Toyota Prius will not stay in gear off an on. It will go into reverse or drive for a few seconds then pop into neutral. This has happened 9 times in the last 2 weeks and always on a hot day after being parked at work. I have to drive home while holding the shift lever in gear. Sometimes if this happens and I turn off the air conditioning it will stay in gear, but not always. Is this a gear shift lever problem?.