UNITY 3D/UNREAL I need help in creating a Virtual 3D vehicle models and environment

Design details: Hi,

1. The idea is to have a small Sandbox like environment (a room perhaps) wherein the 3D car model will be placed in and the viewer can at his own discretion move around and about or inside the 3D car model.

2. There is no gameplay or anything. The idea is to have a 3D car model inside a room like environment and viewer can freely walk around and interact with car. It has to be a VR/AR mix. For eg: A viewer should be able to open car doors, or say look around the interior. We're hoping to have interactive toggles inside the WebApp or Standalone app when a viewer decides to view car model. Toggles like to open doors or interact with various elements of the car. And also to move around freely.

3. The UI is being designed. But you may have to look around for 3D models of cars/motorcycles we prefer.

Also we would like to know if you're designing the 3D car model and a Room environment in Unity3D and lighting it and all that, We want it to be as photorealistic as possible, and to reflect an actual real car model and its variants. We also would like to have it implemented for VR use. PLEASE NOTE: THE DEADLINE FOR THE PROJECT IS DECEMBER 20th, 2016.

1. What is the ETD, assuming you start with this Monday or so?. If we can have a rough timeline, that'll be good. Also. Give us a rough timeline if you've to design 3D models ground up and if you're using existing models from a 3D store or such.

2. We want this to be used as a WebApp and also as a Standalone App for mobile devices. How long would implementation part take? after the Models are set?.

Thanks,
Alay
Ideas for the visual style: As photorealistic as possible
Extra notes: