04 onwards is a 182 (different wheels, twin exhausts sticking out back bumper)
Extra 10bhp comes from a 4-2-1 manifold over the 4-1 used on the 172 and the different exhaust system as well as some ecu tweeks iirc.
early 172's didnt have ESP, late ones had ESP and later ones had both ESP and Cruise Control (my 03 plate only has ESP), all 172's and 182's (excluding cup's & Trophys) have full climate control and half leather alacantara seats (Recaro Seats were an option on late 182's and standard on 182 Trophys)
172 Cup's came in blue or silver (silver very rare) and had 16" Speedline Turini Alloy wheels, some have air con and i beleive silver ones have full climate control? no 172 cups have ESP or ABS. they dont have the half leather seats.
some stuff was removed to save weight, to improve performance, they dont have an engine cover, no xenon lights, no half leather seats (no airbags in the seats eather), no aircon on some models, light weight wheels
theres also loads more info but thats just a quick guide to help you
