3d Prefab on 2d background (again)

I've seen answers for this, but most of those seemed to be about heads up displays, which is not what I'm trying to accomplish. I want a 2d GUITexture background and text, with a 3d prefab rotating in front of it. Here's a mock up of what I want, but I need the car to be a prefab that changes as the steering wheel is turned. ![alt text][1] Any way to (within an existing scene) draw the 2d stuff and this prefab gameobject in the OnGUI? Or am I better off doing this in a separate scene? If it's to be a separate scene, how is this done? With a plane? Or just a single object, camera, and 2d commands? [1]: /storage/temp/25832-tt_sample.jpg