ARCamera Preview Ground Plane

Hello everyone!

I am having trouble deveolping a simple Ground Plane App.

I want to display a 3D model of a car onto a Groun Plane, however, everytime I start the app it looks like the camera's point of view is inside the car, it also happens when I am testing it in Vuforia.

If I down size the car it works perfectly but if I want to use a bigger model it just won't work; I am sure this is a very simple problem but so far I haven't been able to find a solution.

Thanks!!