I don't see it as dumb at all. I have solar PV, but adding a 5.8kWh battery would cost over USD 2k / local currency equivalent. As a result, I frequently have to export solar to the grid (during low demand, mid day periods) and then buy it from the grid when it's already in high national demand (and priced accordingly). I also have a 13 year old car that our family is fast outgrowing. It's used once or twice a week mostly for shopping, and also for some occasional long drives to see family etc. The latter are the only times I'd be at risk of starting with low charge (easily avoided). My next car will almost certainly be an EV, or PHEV. I'm supremely eager to be able to leave it in the garage/on the driveway as a home battery that's an order of magnitude bigger than a standalone battery I would buy and then have to devote attic or closet space to (and have to accept a fire risk for). I'm effectively deferring several buying decisions (car upgrade, battery purchase) until I get a good V2G option that is an all-in-one solution.