Left a note for Loud Car Guy late Sunday night, outside his apartment. Apologized for various bad behaviors on my part, expressed interest in making peace, noted (not in these words) that our ideal worlds are mutually exclusive but that I thought we could probably work out a compromise that we'd both be happy with, and offered to provide cookies and other snacks now and then as a token of gratitude for him being willing to go out of his way to accommodate me. Left this note on top of a box of (store-bought) cookies. My basic intent: provide him with an incentive (which he hasn't had 'til now) to want to do things in a way that works for me. "Make allies, not enemies"; I had lost track of that dictum.
Monday evening, I came home to find his car parked in the same space as usual, but (as I'd asked—and as the apartment managers had asked previously without any effect) turned around, so (a) the tailpipe isn't pointed straight at my window (which I hope will result in less noise), and (b) he doesn't have to do a 3-point turn right outside my window before he can leave in the morning).
Monday night I left him a big bar of Scharffen Berger chocolate and a thank-you note. This afternoon, he parked the same (good) way as yesterday.
Unclear as yet whether this will actually reduce noise enough for me. And he's still declining to park one space further back, which would have a huge effect (since it would mean he wouldn't have to come anywhere near my window) at basically zero cost to him. And who knows if he'll even keep parking turned around. (I did point out that he has to turn around either when he arrives or when he leaves, so it isn't actually more work for him to do it on arrival instead of on leaving, but I don't know if that argument actually had any effect, since it clearly feels to him like more work.) And he hasn't directly communicated with me, so I don't know whether he's expecting to get a reward every time he does this or not.
But this is the first time he's ever shown any willingness at all to accommodate me. Gives me (a tiny bit of) hope that I may be able to relax some about all this, which is the most important thing.
I have one tiny piece of evidence that suggests that perhaps someone else lives in his apt with him, which makes me wonder if perhaps they took pity on me and convinced him to compromise a little. Interesting if so.
Anyway. Another (probably unrelated) noise problem manifested this morning: someone playing loud music early in the morning in a nearby apartment, but I'm not sure which one, because it's not audible from outside, only through my walls and my bed. Thundering bass and heavy drumbeat, not loud but heavy enough vibrations to shake the bed, and seemingly louder through earplugs than not. Also, my shower problem ain't going away. And this latest loud-car development, while a significant improvement, is far from an ideal solution. So I'm still hoping to get out of here soon.
But I'm cautiously slightly optimistic about the short term.
(Also, I may be getting slightly better at falling back asleep after being woken up, an essential skill for me to learn.)
Of course, tomorrow things will probably fall apart again. But it's been a nice lull, anyway.
Oh, I had one other idea: music-studio soundproofing material, to fill my bedroom window frame. I'm guessing it would be very effective; I just need to get on the ball and find out where to get some. But given that I haven't taken the time to track down heavy curtains in the week or two since I had that idea, I suspect it'll take me a while.