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.

Musk is a scammer who has almost no practical understanding of engineering.

He (and unfortunately many after him) forgot about thermal expansion and contraction as well with his dumbass Hyperloop idea. Have a hermetically sealed metal tube with a vacuum run exposed for 200km and let's just ignore thermal expansion. One station would have to move left and right for several meters throughout the day, every day for that, the 200km pipe somehow would need to be able to move about... His "designs" and "ideas" are engineering nightmares

Nah, not impossible people build stellarator type Fusion reactors with large freeform metal parts in that tolerance region that are exposed to liquid helium.