Main differences:
-Transmission went from 8-gear to 10-gear
-Some older models do not have AndroidAuto and/or Apple CarPlay
-Newer models got HDMI port for the rear entertainment system, while older was RCA connection port and SD card
-Newer model got a new amazing updated grill
-I know that newer model got an Active Grill Shutter as standard, but I think it might not be installed at the older models
-Older models might not have the large digital display in the middle of the speedometer
-Earlier models got some recalls that you might need to check, last one was in Sept 2019 for the break vacuum pump and I guess 2018 was not included since they already have fixed it
In general, you may need to check Fourms and YouTube regarding transmission thermostat delete to keep transmission fluid cooler