I ran the BassLink in my previous car (a wagon) and while it improved the low end, I'm guessing it won't have as good of an effect in a sedan where it will have to fight to be heard through the rear deck. As far as installation, it shouldn't be any different than a regular amp install. Its amp accepts both, low and high level inputs. You will need a 10 gauge wiring kit with a 20 amp fuse. Be sure to tap into the pre amp wiring of the Bose system. See my Sub Install Thread
for diagrams that show where to tap into the factory wiring for signal and remote turn on.
I do warn you though, when it comes to audio (much like horsepower) it usually feels and sounds great the first few times before more often than not you end up wanting more. If you think you may want to upgrade later, then run a larger wiring kit so you won't have to do it again. A 4 gauge kit should give you enough room to handle 750 to 1000 watts RMS depending on amp efficiency. Good luck and Happy New Year!