Some more tea leaves to read:
Nissan has confirmed they will assemble the new Micra (a.k.a. March) in Thailand (where the Mirage is built) under the Thai "Eco Car" program. This is the same program that the Mirage is in, where to qualify for manufacturing incentives the cars must be built with small displacement, fuel-efficient engines.
Source: http://paultan.org/2017/01/18/new-ni...thai-eco-cars/New Nissan March, next-gen Note will be Thai eco cars
The next step is to study and plan production for the second phase of development for new generations of the March and Note, including other small cars,” NMT marketing VP Sureethip La-Ongthong Chomthongdee told the Bangkok Post.
So that means both Mitsu and Nissan are building their city cars in the same country. That suggests the door is wide open for platform sharing.