I printed the original X-wing car for my 3yo nephew and it took him all of about a day to break it, which at least shows he was playing with it :). It broke off one of the wings where the wheel was too near an edge.

So I took the SCAD file and made some modifications:

Shrunk the wheel holes (they were way too big).

Tidied the code ... a lot. This was clearly a modified version of another piece of code so I stripped out the bits that weren't needed and re-wrote the code in a way that (to my view) is easier to follow and tried to comment it completely.

Flipped the wings over. X-wings have forward swept wings for some reason.

Split the model in 2 and added a joining piece (so it can still be printed without support).

So here I present my derivative ...

Print the main STL file, you can split off the joint block if you want that a different colour (mine is black on a red X-wing).

Possibly need to drill out the axle and gun holes to 3mm.

Print the Accessories in a contrasting colour (glow in the dark PLA works REALLY well).

Use 3mm PLA (or something similar) as axles

Assemble pieces, its all pretty obvious. Longer guns go at the top as the holes are not blocked by a PLA axle.

I Glued it all together with Superglue to be sure it stayed but it will probably stay together without this.