The 2007 reflector housings will physically fit into the same place/screw holes as the earlier third gen housings.
HOWEVER.
The 2007 lights use one 3157 for stop/tail/turn and one slightly smaller bulb for backup. There is no circuit board style multi-bulb holder. Each bulb snaps into its own housing which attaches with a half-twist to the reflector assembly. The harness is now split so that one 2 pin connector goes to the backup bulb and a 3 pin goes to the stop/tail/turn.
So far, noone has come out with a harness to go from one style to the other, in either direction.
-Daniel