The easiest way to future proof is a NEMA 14-50 50A rated outlet in the garage/carport. This will then let you plug in whatever EVSE you need now or in the future.
Unless you have very unusual driving habits, any of the ~30A 240V EVSEs will probably be ample for any future cars - that would give any modern EV ~200 miles of EPA range overnight, and future cars will likely be more efficient than current ones. It'd also be perfectly safe and suitable for your Volt, though the Volt can only use about half the power the EVSE could deliver.
Unless you have very unusual driving habits, any of the ~30A 240V EVSEs will probably be ample for any future cars - that would give any modern EV ~200 miles of EPA range overnight, and future cars will likely be more efficient than current ones. It'd also be perfectly safe and suitable for your Volt, though the Volt can only use about half the power the EVSE could deliver.