Just to be clear, it's not a "Diffuser" it just sort of (not really) looks like one.
The stock SES bumper has a "Valance" insert and the 3DCarbon rear lip is one molded piece. The black part you see is just painted black to look like an insert.
There are other rear lip kits you can buy, but none of them are worth a crap and they're all designed to fit the SE bumper and not the SES.
2011 SES 5spd #006 >> SR #213
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