I got the '06-'07 wrx decklid from Ray C, had the trim and keyhole shaved, had a Bayson R replica lip trimmed before epoxy and bolted in place, then glassed in. Guy that did the work is Ferdie at Ferdie's Classy Chassis, he just finished my dad's '66 vette resto (the two of them were at it for two years), been at chassis and body for 50+ years.
Main trimming performed was to get the front to sit a bit lower, kicking the lip up more for a bit more pronounced duckbill look. Also had him leave enough of the lower edge visible to replicate the factory decklid sculpting. Couldn't be happier with the way it turned out
Paint was done by a contact of KSpeed, they also did a new OE front bumper as mine was cut hell for previous FMIC set up.