Title says it. I just finished the quest with Jacky's mom in the bar. She gave me the keys for his bike. When I went outside to call the bike, suddenly my car came back. But in the journal the quest "Human Nature" still says I have to wait unitl my cars is fixed. I also didn't finish the "Epistrophy" quest line yet.
Is that a bug?

It most certainly is a bug. When Act 2 started and the Delamain totalled my car for that questline, I found that I can still summon the car even though it's supposedly "under repair." The bug is in the car summoning. It doesn't register what you have available, only what you summoned last time... which happens to be the car "under repair." As long as you don't switch to the motorcycle or maybe buy other cars, you'll still have access to your first car.

Interesting. But for me the car became unavailable after Del crashed it. I tried to summon it several times. It became available again when I received the motorcycle key.

Bug ? I corrected itself , The Heist in the lobby my partner is stuck in corner of desk and pillar and can not move, in the lift the Cop is stuck as well. The text just says Search the cop ? Eventually I killed the cop once I did my partner appears in the lift with me. Until I killed the cop and searched him, my sidekick was stuck until I did the search on the cop.

Weird! I just finished a short side mission and suddenly the notofication came up that I've just bought a vehicle - and the quest "Human Nature" completed has been completed. I don't know what caused that now, but it's fine.

It automatically completes a day or two after talking to Delamain and receiving the Epistrophy quest (you should have a message from Del telling you your car has been repaired).

It ain't that simple tho. Since there are reports that you can't just wait the time out, it's not "just" the time. But it's not just completing this, or that, mission either. As many people completed the missions they've been told to complete by others and didn't get their car back.

For me, it was extremely annoying, since my car trunk stash isn't linked to my appartment stash, and I keep stuff in there - I actually like it, kind of. It's another container so I can do some sorting. Anyways, that's why it was so annoying.

In my game, it completed and gave me back my car after having completed the Delamain car hunt mission, and I was right in the middle of doing the mission in Mama Wells bar, well before I ever got the bike key from her. Just happened on my walk back to the bar from Jackie's garage.

So it didn't trigger because of mission completition. And it didn't just on ingame-time, either. I think it's a mix of both or something like that... so you can't just wait for 2 days and immediately have your car back, you gotta do shit in the meantime or something.