Three really, visually:
02 'Classico' rear wing aerial, ASR
03-04 'Pre-facelift' No aerial, MSP
04-end 'Facelift' bumpers, cup holder
The difference between 'Sport' or 'Power' button is not age related. 'Sport' if skyhook suspension, 'Power' if no skyhook suspension. Although skyhook was optional, I think it was more a 'delete' option in the UK hence 99% if not all UK cars have skyhook and hence the 'Sport' button.
You can't go on the wheels either, the early multispoke wheels could be selected instead of the later 5 spoke wheel if you wanted on later cars.
Agree completely with all this.