Importing from Unity to Blender to make a mesh collider

I am using a vehicle asset pack from the asset store. It includes the FBX file naturally, but when I import that into Blender(v2.79b) the pivot has moved. I want to make a very low poly mesh to use as a mesh collider, but a mesh collider is positioned by the pivot point/origin of the two meshes.

Shown is the difference between the pivot in Unity and the origin in Blender.

What is the best import settings for blender and what export settings should I use?

 

Two suggestions:

1. In Blender, you may need to Apply the position, scale, and rotation to Blender objects before exporting to FBX. Here's a pretty useful guide: https://gamedevacademy.org/how-to-import-blender-models-into-unity-your-one-stop-guide/
2. For low-poly collision meshes, instead of Blender you might consider using ProBuilder to create those within Unity. I've done this and found it to work very well. Just create your ProBuilder object in the usual way, making sure it has its mesh collider option enabled, then when you're done disable its MeshRenderer component on the GameObject. During PB editing, you may find it helpful to clone ProBuilder's default prototype material and make a semi-transparent version of it so you can see your visual Blender model while making the PB model around it.