Hi meeting-influence,

Thank you for the file.

Here is your file back:
CV4_2024_drs_24_ANor_01.c4d

I colored the cubes, in case for follow up questions.

Screen Shot 2024-02-08 at 2.59.44 PM.png

One obstacle was undoubtedly in the "Scale" settings of the objects, being different than 1.0; I would avoid this in animation, as it distorts things down in the hierarchy.

Wheels can make sense in two ways: the axis moves or is fixed.

I have both in the scene and placed a camera on it so it can be easily observed. The camera has no other use here.

I have set the Up Vector to Expression 1, just in case, so it is always calculated after the Align to Spline.

All the best