Saving what you would have spent on maintenance on an ICE car in a separate account would probably amount to the cost of replacing the battery.EV's in general have a lot less maintenance and running costs. I know some automakers have also developed regenerative suspension systems (Audi) but I don't think its been implemented in any production vehicle yet.
If what we are seeing from Nissan is any indication, most EV manufacturers will have to explore these kinds of solutions for unused battery packs. Entire stadiums and various city blocks are always being powered by second life Leaf batteries.I hope that Porsche and other premium EV manufacturers prioritize a second life for removed batteries. Whether this be using them in their charging stations or providing an energy supply in places that its needed.