obviously not an S owner here, but my .02 -
During test drives, we sat in a dealer LX, S, and EX-P fully loaded with every accessory add on.
we were not impressed with the LX at all. The S was / is nice and is a very good value, by my wife likes certain ammenities that came standard with the EX, such as the auto tailgate. We were indifferent about the (Gray vs faux wood) paneling on the S- vs EX+, but I’m a bigger fan of the wood. We also think that the button placement and infotainment enhancements with the EX+ trims were far superior than that of the S- trims. We also liked the comfortability of the seat upholstery on the EX+ trims.
Of course, on EX standard, you get the 18” rims. That may be a bummer to you since you mentioned that, but we wouldn’t trade what we got with the EX amenity wise (EX-P in our case, so 20s) just because it comes with 18s.
you can always buy an aftermarket rims/tire combo and/or spacers which would cost more than an auto-tailgate kit, but in the long run, imo, that would be the better route.