many would like to have the option to disable ERDTT. It is hardly needed for someone in Canada who only has a 5 mile commute, yet it it will run the ICE to heat the cabin at a time that the driver doesn't care if the heater xxxx a lot of range. a 10 mile round trip could be done purely on electricity
For me, the show-stopper is the seat. To "re-Volt" after my current lease is up, the new one needs to offer adjustable seat angle for the bottom cushion (rake). It doesn't have to be power, but it needs to be adjustable.
Other "nice to haves" include having upgrade options for adaptive cruise, glass roof/sunroof, and a spare tire kit.