Sorry it took so long to get back to you on this question...
I'm no longer using the factory sub because it's not needed with an aftermarket sub.
the wires I splice are before the factory bose amp...my reasoning (although it's not confirmed, just my assumption) the frequencies are "more...
This may be an obvious answer question but I am having difficulty locating the correct vaccum line to cut...more than likely because I am a n00b at engine work and can't locate the BPV. Would appreciate some info and possibly some pics to help find it, 08 speed3 if that makes a difference. Thanks!
http://www.mazdas247.com/forum/showthread.php?p=4059954#post4059954
I ended up doing my own quick how-to and the pictures are there...let me know if it is enough info.
Tools Needed
14 mm socket
10 mm deep socket
Precision flat head screwdriver
Socket Wrench, preferably 3/8 drive w/ extension
Wire Strippers
Wire CrimperPreparation
Make sure you have enough room to open all doors completely
If you are working in a garage or crowded area, make sure you have an...
I installed my aftermarket amp without going behind the head unit...the BOSE amp is right under the driver's seat & it is much easier running & hiding the wires from there...if anyone is interested I will post pics.