Do we know the make/model of the turbo used in the ES?
Lap3 already has a bigger turbo option. Others are working on some. I know SXTH is working on a kit to upgrade to the Veloster turbo.I am sure tuning companies will offer a bolt-on turbo kit in time. Between that, a turbo back exhaust, enlarged intercooler, and proper CAI, that will definitely yield some significant gains on this platform.
That said, I'm staying stock.