|An existing plant in the same area as the new one|
This makes sense as smaller vehicles are less profitable, so spreading development and production costs over two brands will improve the bottom line. Smaller vehicles do not sell that well in North America, so another reason to share such a factory. Added to that the lower wages in Mexico which will again assist in making the venture more viable for both.
The plant's 300,000 capacity will be used to make three Infiniti models from 2017, with MB matching that with three of its own from 2018. This is part of a collaboration in the whole process from research through to production between the two marques.
I have been going on a bit lately about greater cooperation between car makers to bring down costs. This sort of thing will give MB what Audi already has, sharing costs with other models. VW does it in house, whereas MB with another company. Which begs the question where does this leave BMW?