Unfortunately, you’re never going to get veneer to follow the curves of the existing plastic. If you could, it would be crazy crazy expensive. Veneer flitches are stitched together with glue and a “paper” seam tape. It’s brittle and works best when applied over flat substrates.

I’ve seen wood veneer vacuum formed over curves but it’s on very expensive wood veneered items items. No one is going to spend that kind of dough on a 15 year old car.
lots of comments about the price of a 3D printed Double din. If this was a possibility, it would be many times the price of that. The most cost effective solution would be a wrap. But that too poses a problem, the wrap may prevent the pieces from snapping back into place.

Good luck on this project, looking forward to seeing your solution.