Waterbourne lacquer, but that might not spray too well out of an airless.
Probably the glossiest "Gloss" or "High Gloss" I used was the old Muralo Ultra, which to my eye testing on two scrap pieces of trim just by brush leveled as well and was almost exactly as glossy as gloss white Rustoleum, if not moreso. However, Muralo is out of business and the California Ultra imo isn't a match, and there's no high gloss version anymore either.
I have very little personal experience spraying, but I think the issue with trying to get a "carlike" finish out of house paints might be less the actual paint itself, but more the sprayer, I'm not sure an airless can really atomize paint the same way an HVLP style gun can using compressed air. People spray stuff like Advance out of HVLPs and get it really nice looking, sometimes with some thinning, but if you just ran out of it an airless you'd get way more orange peel, etc. Some people are very good at using an airless, and have the right tip setup, etc, etc, but you might need to go HVLP to get a carlike finish. Also too, in automotive as far as the primer goes you're generally wetsanding to at least 400-500 grit before any paint gets on it, so how smooth it ends up is largely dependent on that and less the actual top coat, too.
You can still make something very glossy without necessarily spending the labor in prep, which a lot of new cars do now, they have glossy finishes but often tons of orange peel.
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Brand new BMWs are coming with that much orange peel from the factory now, but they're so glossy you don't notice it until you're up close.
To get stuff to be "show car' ready it's a big process of cutting, buffing, etc, usually with wetsanding starting at 1000 grit, going to 3000 grit, then rubbing compounds and waxes.
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That car was painted with Rustoleum applied with a foam roller, 5-6 thin coats with the paint thinned down to milk consistency. But he got it to looking "show car" nice by just spending massive amounts of time wetsanding and cutting and buffing it.
I don't really know how FPE and all that works for house trim, same with lacquered drywall, etc, but I'm assuming it's a similar crazy laborious practice.