I installed an RT3 instead of a RD4 in my 407. I used a 307 screen so I solved the problem using hardware as Peugeot ask about 1200 euros for a correct screen which is mounted inverted relatod to other vehicles. I give you my totorial on how to do it. Look at the last pages.
http://personales.ya.com/ems0/Instalacion_de_un_RT3_sobre_RD4_archivos/frame.htm
It is not a problem with the fiber, its a problem of programming but RT3 upgrades do not detect the 407. This problem has been cited in different forums. There were no solution until last moth. I solved my problem.
