Very unusual problem, perhaps electrical problem

The last couple of days, my STS has been acting very weird.
1. My rear lights start flashing. It is as if my hazard lights are blinking. It has done this three times. The only was to get it to stop it is to turn the ACC on. Perhaps this is related to number 2.
2. I went to start my car and it died. That has never happened before. I tried again, and it turned over, but then turned off. It turned off as if someone cut the power. For about 3 seconds, all lights and accessories were turned off. Then, the radio turns back on for 5 seconds, and then all power is cut for 2 second. Over and over again. It keeps doing this until I push the "off" of the push button start. I actually pushed it a few times, but I needed to push it when the power was turned on.
I went through this for 20 minutes. I got out, popped the hood, walked around, locked the car, tired everything again.
When trying to use the remote lock/unlock, the car would not respond.
Finally, I got back in and the radio stayed on. I pressed the on button and it was like nothing had ever happened.
The best thing I could compare it to is it was like the car was having a seizure every 5 seconds.
Perhaps this was a weird, once a year fluke. However, it started doing this again at the gas station. Lucky for me, the car corrected itself.
3. I did get a message that said service vehicle soon. However, I did not light up the check engine light. Normally I get a service vehicle soon at 10% oil life, but mine is at 50%. I cannot remember, but does it normally tell us to service vehicle soon at 50% oil life?

So what does everyone think? Anyone experience something similar?
I am bringing it to the dealership soon for something else, but they are not very smart, to put it simply.