This is an '04, 129k on it, I THINK I have an answer, but it's going to be tough to prove without throwing a code.
She's been taking it to Jiffylube for her oil changes and getting freaked out because they are always trying to sell her shit. When they called me about the van they asked me to get an air filter for it because it was dirty as hell and they didn't have one. Got the air filter and got to looking, the old one was dirty on the top, the air comes in from the bottom? Odd, but ok, put the new filter in and go to seal up the air box, the nut for the front bolt is gone! The air box never got sealed up and most likely the jackwagons at Jiffylube messed it up to start with! We pulled the MAP sensor off, right behind the air filter, and cleaned the hell out of it, but...............
She and I had a chat and it's NOT EVER going back to Jiffylube again!
Random parasitic draw sounds like one of the ECM's isn't shutting down fully for some reason. A good wrench shoulb be able to "map" it with a good scanner, either pulling up old codes, or watching to see what doesn't shut down properly. Just a little FYI, there is an ECM for the motor, the tranny, the ABS, the suspension and the chassis. Plus whatever they threw in for the hell of it! Anyone of them doesn't want to shut down now and again, dead battery! I also found out that Toyota is rather slow on TSB's (technical service bulletins) and it might behoove you to call around to a couple of dealers, besides the one you've gone to, and ask about the problem you are encountering. I'll be doing this tomorrow on my problem, really pisses the dealerships off when you come in knowing more than they did, they start jumping through hoops really quick!
I hope that helps a little at least Greg!