Is it possible to get factory wind tunnel data on your vehicle ?
 

Probably not, but why ?
I would think after a design is a decade old, there is no information that is proprietary.

It sure would be helpful to see the problem areas on our cars and see what aero tricks were rejected for styling.

IMO, no financial upside, and huge competitor marketing downsides with a rather ignorant customer base on the aero subject, sadly.

I don't see how it would show the paths not taken, unless they disclose the entire design process.

OTOH a library of 'as-built' data point clouds piped through a standardized CFD analysis could produce a searchable database. Given current compute capabilities.

Good SAE and IAME papers show the complete aero development of some cars. However, unfortunately, not very many.

Sometimes it can be found in the manufacturer's sales brochure so you can see if that can be found online.

For sure, but it should usually be taken with a grain of salt. Especially if using it comparatively across manufacturers.