I have been experiencing a really weird problem for the last few weeks on my '06 GS430 and haven't found anything similar anywhere...
The L/R sideview mirror selector resets itself to "neutral" (i.e. neither side is selected) after the car has been shut down for some time. By "some time", I mean if it's in my garage overnight, then the next morning the L/R sideview mirror selector will reset to neutral. If I set it, drive to work, and then later go to lunch, it will maintain the setting. So I guess, after 8-10 hours it will definitely reset, but if it's 3-4 hours, it will definitely maintain it. Not sure what the exact time break between reset / not-reset is, but you get the idea.
Besides this situation being highly annoying, the "neutral" setting for the L/R switch also disables the sideview mirror tilt when reversing.
The *only* thing I've noticed different about the car around the same time the problem has started is that I think that my battery is getting weaker (it takes a few more turns to start the engine than usual). I haven't had a chance to have the battery tested yet, but was wondering if folks out there: 1) have seen this L/R problem before; 2) think that it could be related to a weak battery (all other electrical systems operate fine).
Any thoughts/comments would be highly appreciated.