Like I said though, even Archer shouldn't be able to do this.
Plus even as Archer's daughter, I don't think he'd necessarily pass down his ability to project, especially to that degree, for certain, as a lot of that is determined I think by his personal circumstances. She'd be likely to reinforce really well, sure, but projection on that scale? For most magi, it shouldn't be plausible, and even as Archer's child, Sakura should fall under the "most magi" category, because, again, it's highly unlikely he'd pass down his projection, as that is all largely unique to him and not genetic.
The problem is that, even as a mundane object, it's large, has lots of small parts, plus fluids to get in there in order to get it to run properly. That would take a ton of prana. To be able to project a car would be getting closer to miracle territory, which, again, even Archer, who can repair kitchens and entire rooms back to brand new using his magic, shouldn't be even able to do.