That's correct KENMO. I guess it works both ways but I prefer the MoI->Blender path for a couple of reasons:
- I like having the final mesh in Blender where I can experiment with materials and get it ready for rendering.
- It's easier to construct large curvy surfaces in MoI following the blueprints with reasonable accuracy. In Blender you have to account for the movement and "shrinkage" of vertices when you turn on the subdivision modifier.
- The lack of materials and complex lighting in MoI, sometimes makes it difficult to judge if you're correctly modelling a shape. In Blender you can do a quick render and compare with reference photos, and then make adjustments.
- Since I model only half of the model, Blender helps with that by having better mirroring functionality which you can turn on/off anytime.
- Some final tweaks are simpler to do with polygonal modelling where you can just drag some vertices around.

Hope that helps. I also just finished another car with the same workflow. It didn't turn out that great (and I forgot to model the mirrors