Like many of us I find that most manufacturer’s models are rarely useful for design or construction documents as they are excessively complex and lacking much critical information needed during the above phases.
Accordingly, I nearly always end up creating my own simplified models and over time try to value add data to make them more informative.
I have attached one model I just uploaded to 3DWH
LG Washer Dryer
But I am curious how others have approached the issue of manufacturers models in Sketchup.
The objectives I try to embed in my models are
- Accurate size
- Units used
- Any service attachment points
- Simplified form (minimizing curves)
- rational object axis origin
- glue to surface where appropriate
- weblink to the Manufacturers site
- Manufacturers model code ID
- Tags for 3D form (3d), 2D outline(2d), Space envelope (-seto)
PS shout out to the SketchUP 3Dwarehouse team for the improved interface with the enhance preview window with scenes 
and happy for any suggestions and feedback!