A little history: When I bought this car at the end of September, it worked perfectly well, except various items (like the radio clock) would lose power when I turned off the ignition.
Turned out the IOD (Ignition Off Device) fuse had blown. Which maybe shoulda tipped me off. I replaced that, and everything was peachy for a couple of days.
Then the battery died. Hard. About the same time I discovered the radio would come back on about 10 seconds after I closed the car door.
When extensive trickle charging failed to do anything for the battery, I replaced it. The radio started behaving normally. Life was good.
Then it started doing it again. Right after a ride where the radio started going on and off as we went over bumps. So. The impression I got was that (1) there's something floating loose in the radio, and (2) the "something loose" puts it in an odd software state. It probably worked fine after the battery was replaced because it got reset.
Of course, it could be the power control module instead, but it only seems to be the radio that misbehaves. It's not like the dome light comes back on.
My behavior lately has been to turn the radio off when I park, which has mostly seemed to work, except I forgot a couple of times this last week. I needed a jump after the Sunday show, and forgot again Thursday. It didn't die then, but it... wasn't happy. And I didn't drive it too far after starting it.
I had another issue with it yesterday - I was going to drive to the bank, and it wouldn't start - but an hour or so of trickle charging seemed to fix that up.
Except it wouldn't start again today, and now 2 hours of charging have done nothing.
So, just to be sure, I've pulled the fuse for the radio. And put it back on the charger. I'll likely keep the fuse pulled for a week or so, just to see what happens.
Though I know I'm gonna get some grief for that.
I supposedly have this amazing warranty that covers everything, including the radio. The problem is, it only covers repairs to the radio. And I know of no-one out there that repairs them.
Not to mention the fact that most mechanics are not exactly top-notch electrical troubleshooters. Most of my experience has been on the order of "we'll replace part A," followed by another "we'll replace part A" when the same thing happens a few weeks later.