Errrrr not quite - the "Phase 1 & Phase 2" thing was created by the car media/magazines, namely Evo when they did a FRS buyers guide - the reason behind it was things like the AF ecu map, stitched seat bases, pink throttle thingy, interior dash clock light dimmer, etc, and they listed these as "phase 2" updates on the later cars that came off the production line, compared to some early build cars that didnt have them.

However as has been proved on the RSOC countless times over, most of those items were easily retrofitted to the early cars, such as the stitched seat bases that some dealers paid to fix to cars that suffered from sagging seat bases & most FRS which left the factory new with the AE map were automatically given the AF map when they went in for a service

My FRS is one of the late 2003 built cars & has all the "phase2" items but not the stitched seat bases - there are also 2 '04 cars on the RSOC that do not have stitched seat bases or the interior dash light dimmer but they are late cars off the production line & therefore would be referred to as "phase2" if you believe the mags

Anyway back on topic