Poster here. We would have loved that, and it was one of our first proposal - a QR code or some kind of marker. However, the client is understandably very controlling on the aesthetics of their wall as a central element of their scenography. We would have pushed for it again in the last resort, but would probably have lost the contract.
This is completely offtopic, but I would bet it was a government-funded museum.
A reasonable institution would have worked with you to find an acceptable compromise, something much easier to implement with a small sacrifice of aesthetics.
Anyway, great work, and thank you for taking the time to share it!
Really? I would much less expect a government museum to be particular about aesthetics. Privately run museums/collections/exhibitions on the other hand tend to have very finicky owners -- after all, they're putting up their own money to achieve their vision, and so of course they tend to not want to compromise on how it might look.
Sounds like the client cared a lot about the user experience being smooth (they declined the solution of presenting the user with the narrowed-down choices of which car they took a picture of), and I think adding a bunch of QR codes to this aesthetic wall of car illustrations would not align with that goal.
Or just a human-readable label with the model and year on it. Visitors would not need to mess with gadgets to read the labels which would be a huge usability win.