I'm not going to lie: cabin noise levels are definitely higher. I knew that going in, of course. The VX sounds much meaner now...and after living with it for a couple of days, it DOES seem to have more HP. It gets up to speed sooner, and seems to 'coast' farther when I let up off the gas.
I'm going to have to try some sound-deadening material in the rear cabin. I wanted to do it anyway, but now I've got some real incentive! I'll try removing the rear seat and then really maxing out some RaamMat under the carpet and behind the side panels.
No regrets. I like the new sound.
OEM roof rack, Thule Xpedition 696 rack, Rancho RS9000 shocks, OME 913 coil springs, 3" lift, American Racing Teflon Chambers wheels, Yokohama Geolandar HT/S G051 tires (275/70/16), Energy Suspension greaseable bushings, steel-braided Kevlar-reinforced brake lines, WeatherTech wind deflectors, Malibu 18w driving lights, Plasma SuperWhite 100w headlights, NGK Iridium plugs, K&N drop-in air filter, Optima Red Top, Psychos2 rear-door subwoofer enclosure w/CDT Audio 10" sub, Blaupunkt subwoofer amp, iPod Video 80GB, Kenwood KVT-617 DVD head unit w/7" motorized touch-screen, Kenwood GPS HD navigation module, Kenwood iPod adapter, Kenwood back-up camera, Sirius radio, Flowmaster Extreme Off-Road muffler (black diamond-plate steel) w/ carbon fiber tip, Ford Taurus OEM cup-holder/coin tray (single-DIN/lower bay), personalized license plate "ORBITAL", 3M window tint, debadged, removed rear seat, custom 'radiation symbol' side magnetic signs, VX Concepts front skid plate