Just be upfront and open about it and sell them as POSITIVES. Be your own salesman for these modifications. That is what I did when I traded in mine. I guess it is going to depend on the dealer though...GL... but have questions.
Has anyone traded in a Volt with a modified EVSE? (Mine's stock '13 with adapters to use on 220/110.)
Has anyone left their ERDTT mod installed?
I'm concerned they may frown on these. Granted the ERDTT mod is easy to remove, but don't want to have issues with the EVSE.