Geom0
- Lod0
- - Inside model (all cockpits)
Geom1
- Lod0
- - Outside model detailed (main model you're making now)
- Lod1
- - Outside model less detailed (if the object is >100m away)
- Lod2
- - Outside model low detail (if the object is >200m away)
Geom2
- Lod0
- - Wreck model detailed (main model you're making now)
- Lod1
- - Wreck model less detailed (if the object is >100m away)
- Lod2
- - Wreck model low detail (if the object is >200m away)
You can also create an even lower quality Lod3, which I think your model needs cause it's pretty detailed and big.
Then you'll also need four collision models for the Main model & wreck model.
Col0 = collisions with bullets
Col1 = collisions with people
Col2 = collisions with other objects
Col4 = collisions with bots
Then you'll also need to separate all the moving objects into the proper hierarchy and name them correctly.
Making the model is about 1/4th of the workload