I don't know how the stock nav is closet up, I've never used one, but my head unit has an external mic that's sitting right underneath my rear view mirror. When I had just the exhaust it wasn't a problem at all. I would say that my headers just about doubled the volume inside the cabin.
Sent from my iPizzle using magic and new-fangled science stuff
__________________
VLEDS | Evo-R | Moddiction | CF Hood Struts | F.I. CF CBE & LTH | Stillen CAI | NST Pulleys | UpRev | Z1 | M7 | Status | Forgestar | PSS | Whiteline | SPL | SPC | Kenwood | Zenclosure | Kicker | Alpine Type R
|