If it helps, we have confidential files submitted to us by major manufacturers/automotives all the time. We know how to treat these confidential files.
Yes, having the CAD program can get around this because problems can often be duplicated with some aspect of the model that is non-proprietary, such as simple shapes that do the same thing. If you don’t have the CAD program, then it is harder to help us reproduce. However, please submit bug reports because we can at least see if there are multiple issues cropping up - even if you can’t hand us a file.