to build it to that accuracy the car would have to cost millions

To build it with that accuracy would be physically impossible. Guess he forgot about thermal expansion and contraction. Guess he forgot about the weather…

I mean, it says cybertruck parts, not the whole thing including assembly. Certainly possible for some manufacturing processes under given conditions to produce parts with ±0.005 tolerances like laser cutting or precision CNC machining of small dimensions. But it’s obviously completely unrealistic given that most parts for a car will be of large-ish dimensions and stamped, injection molded, cast, forged, extruded… none of which lends itself to IT grades better than 10, far away from talking about microns.