JulioC05/RA-Cars ? reverse-engineered prompt

Build me a Unity based augmented reality car app in C# that lets a user place a car model into the real world through the camera, move it around, rotate it, and view it from different angles.

I want it to feel like a polished demo app, with a simple start screen, clear instructions for placing the car, and basic controls that are easy to use on a phone. Please make the car placement feel stable and responsive, and add a nice presentation so the model looks good in AR.

If you need anything current from Unity docs or AR setup details, look them up online and use the latest approach that makes sense. Keep the project clean and runnable in Unity, with the main pieces already wired up so I can open it and test it quickly.