To be honest, if you ever had installed some audio equipment in any car, it is quiet easy. You need to get a + wire from the battery to the boot, and then the signal wire is taken from the BOSE sub in the side of the boot. I chose to leave the bose sub connected together with the basslink, which I crossed-over very low to give it only the lowest frequencies.
In my opinion, it sounds quite good, since now I have the bass in 0 in the head unit so the rest of the speakers sound quite clear due to the lower bass level. It is no SPL king but I grew tired of that, I did not want to tear the car apart.
This is how it looks (I made a new floor in MDF, I did not want to drill the OEM one which is quite soft)
This is how the wiring looks, I covered all of it in black tubing. I installed the remote bass level in the lower part of the dash (above the dead pedal). I did not drill any holes at all.
If you have any doubts, you can PM me! Everything is quite simple to dissassemble.
