I agree with Kim -- it's not clear what this description means without more context. A "lift" could perhaps refer to any kind of vehicle ("can I get a lift?" = "can you give me a ride?"), but it's not clear whether the writer means something specific by this word. My guess about "turned in, turned out" is that Kim is probably right. To "turn (something) out" usually means to make it point outward, and the term is often used with certain items of clothing (you "turn your collar out," for example). To "turn (something) in" can mean to make it point inward, and clothing can sometimes be described this way as well. Certain shoes are sometimes described as having the "toes turned in." So it seems likely that "turned out, turned in" means that their clothing is properly arranged, with some parts turned out and other parts turned in.

It could be a way of saying they were all suited up and ready to go. More context is needed to understand what sleek lifts are, which may help unravel the meaning of turned-in. I have never heard the term & I’m a native English speaker. There was a saying years ago that went: tuned in and turned on, which meant ready to go.

It seems to be something like this: "the flawlessly made-up, AS A RESULT, BECAME in riders of sleek lifts"