They activate as soon as you put the car into reverse.
Otherwise, if you need to use them to drive forward into a spot, you have to press the button to activate them manually.
They will turn off automatically after you drive over 15km/h (or some set speed, can't specifically remember if it's 15 or 25 etc).
I have a DP, but the cat-back is stock. I'm sure SilvrFoxX is still stock though. It's only half sound though. The other half is how porky the R is but how fast it can start moving... makes the concrete floor of the multi-deck car parks "bounce" quite a lot. (disturbingly noticeable if you're standing or sitting outside of the car as someone else drives it by).
Yeah, six months was hard enough. 12 months... damn. But so far I don't know anyone who has actually waited that long... most of the guys I recall being told that, it has come in 8 to 9 months.
You quickly forget about the wait once you have them though
Bookmarks