1.) Trophy yellow was available right up till the place shut as was never dropped.The Rover 25 came in Dover White, and for a brief time MGR offered it as a colour request option on a ZR for the EU market for a brief period in the 04MY guise before promptly dropping it from the range (soon before Trophy Yellow got the chop), I'm not sure if any actually materialised though.
Well there's been plenty of 05 platers ZR/ZS/TF in Trophy Yellow about all over the place.From memory, Trophy Yellow was dropped I'm afraid. Somewhere in my little army of MG Rover bits I've got the brochures with it removed, and I remember having a few discussions as to what was on the way to replace it, if memory serves me correctly it was not long after the Trohpy and Trophy SE models appeared (in fact you'll notice that all the yellow Trophy special editions on autotrader at the moment are in fact 04MY cars with changed rear lights, although I'm fairly certain a few genuine Trophy ones do exist, but you won't find any late build ones.)
could they not be o4 models tho registerd on 05?Well there's been plenty of 05 platers ZR/ZS/TF in Trophy Yellow about all over the place.