I've already taken her back to the vet to check for any medical problems that might cause this. She obligingly did not pee in my car for this second vet visit, and she obligingly did pee on command for the urinalysis test. But the urinalysis results showed that there's nothing wrong with her. She has no bacteria in her urine, no crystals in her urine, no sign whatsoever of the slightest medical problem. She's merely, shall we say, Incontinent by Choice.
Her kitty litter and her food were both the same brands she's had for ages, and her litter box was plenty clean. The vet wanted to know what stresses she might be feeling that could drive her to "express herself" in this way. I came up with nothing at all other than boredom. It would make a great deal more sense if she started behaving this way after being moved to a new household, having to share her home with Susan's two dogs and two tanks of fish and a temporary hamster. That's the sort of situation that often leads cats to behave this way. But I haven't moved yet! Stardust hasn't been anywhere near the dogs in something like six months. She's living in the exact same place she's lived since she was eight weeks old. Nothing has happened that should have upset her in any way, unless it's the fact that I leave her alone for eight hours a day on weekdays and then I leave her alone all weekend too.
It was unclear what I could do to fix this, since she already had ten million toys (not that she seemed to take much interest in any of them, most of the time). Bringing her with me to Susan's house every weekend would mean subjecting her to hour-long car rides, dogs, and regular uprootings from her territory, while running a high risk that she might pee in my car again, or pee all over Susan's duplex. And Susan can't easily come here for the weekend instead, because of her dogs. But we certainly didn't want to stop seeing each other because of our pets! So I tried all the standard approaches, like pouring cat pee enzyme cleaners all over everything and replacing her kitty litter with Cat Attract litter. Stardust was distinctly unimpressed. She showed no attraction whatsoever to the Cat Attract litter, and continued peeing anywhere and everywhere other than the litter box.
The vet mentioned that indoor-only cats seem to do this more than indoor-outdoor cats, and that turning them into indoor-outdoor cats usually solves the problem. But I'd have to get her some extra vaccinations to make her an indoor-outdoor cat, and then she'd have the vastly shorter life expectancy of an indoor-outdoor cat - and anyway, she's been indoor-only for so much of her life that she's now utterly terrified of the outdoors. If I take her outside, she just huddles up next to the door and mews plaintively at me until I let her back in.
My mother said that various pet-training shows she watches on TV have resolved the behavior problems of indoor-only cats by presenting the cats with elaborate cat trees to alleviate their boredom. So an elaborate cat tree is what Stardust now has. I found a huge cat tree unusually cheap ($83) on eBay, which arrived today, and I spent this evening assembling it. I also tied a bunch of cat toys (purchased separately, bot from eBay) to it with twine. It's supposed to go all the way to the ceiling, but currently it doesn't because there are some minor issues with incorrect screw sizes at the very top of the tree. For the most part, though, it's functional. Stardust is not quite sure yet what to make of it. She's a great big fluffy 12-pound cat, and she seems not very confident that all levels of the cat tree can hold her weight, so she's avoiding the higher levels of it so far.
I hope she decides she likes it. I hope (rather desperately) she loves it so much that she goes back to being Litter-Trained by Choice instead of Incontinent by Choice. But if nothing else, I guess this purchase has at least made it now abundantly clear that I'm not a big follower of B. F. Skinner. With this sort of precedent, it's a wonder if you people don't all show up at my door tomorrow, invite yourselves in, and pee on my bed, just to see what expensive gifts I might buy you if you did.