under the dash on the drivers side there are a bunch of wires in a nicely wrapped harness... problem is they just dangle there... i found that by securing them with a few zip ties the rattles went away...
as for the rattle in the rear of my king cab... still working on that 
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05 4X4 Nismo KC 6-Speed Mods: PXNI AAI-NIS Audio input box, XTR7CK Sirius Sat Radio (dash antenna & custom radio mount), iPod integration, lug/spare/gas locks, Silverstar 9007ST Headlights, Full Synthetic Swap (engine/diffs/tranny/xfer case), OEM Rubber floormats, Flowmaster exhaust, K&N 63 Series Intake w/ an AEM dryflow filter
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