I've had many automatics, mainly Merc and Volvo ones, although I had a Civic ESI Automatic a few years ago too. With the
CVT you literally feel nothing in terms of gear change, if indeed there is one. There is a slight jerk when the engine kicks in again after turning off when stopped, but that's about it. It doesn't actually change from electric to petrol because the petrol engine is always going. It never cuts into electric only mode.
I can't advise on installing accessories I'm afraid, I'm not that technically minded in terms of adding things to cars!