I'm pretty new to the whole car audio scene and recently purchased and installed 2 pairs of JL Audio VR-600 CSi comp sets in my doors as my first component of my audio sys. Bought a JL Cleansweep and a Profile AP 1040 4chan amp. Was wondering if i would need a signal summing device for my 08 or if it would be and easy install. Any help is much appreciated. Thanks in advance.