I'm going to play contrarian: if radical leaps in performance are available through battery gens 2.1 thru 2.3 which offer exact volumetric fit (or involves only a suspension tweak for enough clearance) why not try to squeeze a 2017/18/19 out of the existing Leaf tooling with just a power battery upgrade, and maybe a skin job and electronics tweaks?
Tooling is crazy expensive, and volume production per re-tooling is the key to auto-industry profits. The Tesla S debuted in mid 2012 and there's no talk of a redo of of much that's dimensional/tooling related, but all kinds of progress in battery, power delivery, and motors.
Is there anything inherently outdated about the rest of the Leaf, that a 80% to 100% leap in capacity to 60kWh can't "solve"?
Bad range? Double it with 60kWh and underprice the Bolt with a proven design
Stale styling? Skin job, not all new.
Out of date electronics/controls? Swap a few modules
Need big weight chop? Carbon-Alloy hybrid rims or a carbon fiber floor pan might do it (and give you clearance for that tall 60kWh battery
I think you could just as easily see a second low/sporty 4-seat Leaf "dropped" onto the current Leafs floorpan.
To me it makes sense to keep working the battery and the roofline and not much else:
- Leaf Sport 4-seater (low-roof version; low drag, cutting edge styling but also ceiling too low for passenger #5)
- Leaf (today's model, but twice the range)
- e-NV200 (big empty box sitting on same floor pan as above; maybe a gearing change to be a practical 6/7 seater)