Does anyone have RT cats with the stock exhaust ? I'am seriously considering getting them, BUT worried about a major sound increase while crusing. For me i think the stock exhaust is perfect from a sound perspective..I guess the real test would be "would the wife notice a differance" ???
PS the z-tube passed the wife test with HIGH marks

 

it passed as in she didn't notice, or she liked it. If it's the latter, then get them... She will notice that it will be a little louder..

04' G35 / 6MT / Tein Basic Coilovers
Volk 19" GT-7 Gunmetal

 

she didn't notice any increase in sound from the z-tube, but she's always commenting how cool the exhaust sounds. I guess she wouldn't mind a few db increase in sound as long as it's not a consistant droning or increase in sound while crusing between 50-60mph.

 

The sound will be slightly louder, but the wind noise will generally negate any annoying droning sounds at cruising speeds.