2007 honda civic ex, 4 door

The girlfriend wants to have D3 into her 07 civic EX 4 door, What metra harness am i suppose to useHow do i know if its amplified or not?  i know the metra dash kit is  7871... but  i dont know if the harness is the  1722 or the 1727

Take your VIN to the dealer. They'll be able to tell you exactly which stereo came in that car. Did you look for the amplifier? The 1727 is a 17 foot long harness, so I'd check in the trunk for an amp... If there isn't one, then it's not amplified. The 1722 appeared to be for the Prelude with amplifier, and that's just a pigtail style... (However, I'm not exactly sure this is the proper harness for your car, I'd check again...) I wasn't able to find your exact harness. (The Metra Website fairly sucks...)It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."