Although I own four or five airbrushes, I still like to brush-paint the occasional model airplane, especially if it's 1/72 camouflage. There's something very satisfying about it. By the time I glosscoat it for decals, and then flatcoat after the decals, you can't tell it's brushed.
On cars, I'll always either rattlecan or airbrush the body and the engine block/heads, but still from time to time I'll brush-paint the interior and/or chassis. And of course many details.
If I HAD to brush-paint a model car body, I'd do it in flats, and then spray a glosscoat. I THINK I MIGHT be able to get away with that.