Saturn won't shift out of park on hot days

It sounds like your body control module is going bad really common for those to go bad on those cars. Usually you will door locks inop keyless entry inop fuel gauge inop no starts inside lights flashing etc. But I have seen them not going out of park the security light flashing.

Because electronics fail at higher temps when they fail its a computer inside a hot car I have replaced so many of those I have lost count.I worked for saturn repairing cars for over 16yrs iam a factory trained saturn tech trust me when I give my opion on what I think is wrong with your car.I have seen those bcms fail over years time only acting up when hot cold etc even just every once in a while.I have also seen them fail without warning and the car justs gets towed in and won't start. Welcome to the wonderful electronics and computer world thats what makes the new cars harder to fix intermintant problems like that. Iam also a GM EV1 factory trained tech the full electric cars saturn used to sell. They had 7 computers over 500 trouble and when things failed would sometimes set like 50 codes in more then one computer. They also had 26 batteries that when they went bad were a pain figuring out which ones went bad.

As long as the bcm isn't keeping it from starting you can get it out of park and drive it. Take a small pocket screwdriver and pop up th shifter boot you will see a white lever/arm if you toggle that arm it will move out of park. If the bcm wont let it start though it wont do you any good over riding the bitsi solenoid like that. Your going to have to get it fixed soon no telling when it will leave you stranded some where. Also your going to have to take it to the dealer to get it replaced because it has to reprogramed with the correct mileage options etc.

I wouldn't question Saturntech9. His Saturn answers are always "spot on".