i just bought a 2006 wrx 2.5 TR
wanted to know if the sti spoiler would fit on this model?

Yes it will - you will have to drill holes though.

Best option is to find an STI owner willing to do a trunk swap.

Just a little warning.

Nothing makes you look more like a poser than this mod.

word of warning, do a trunk swap, and make sure you also change the springs that lift the trunk or yours won't stay up and the poor guy you traded with will be launching stuff off his trunk for miles