lol, beat me to itThe problem with tapping into the speaker wires with a LOC is that a lot of the bass has already been filtered out by the Bose amp to go to the factory Bose sub. If the LOC can handle the wattage, tapping into the signal to the Bose sub may produce satisfactory results. The problems there are (1) it's a DVC sub and (2) it's a small sub so it's crossover has been programmed accordingly and this may leave some to be desired with a larger sub system.
I've found pictures and wiring diagrams before, but you can tap into the low-level, full-range signal going to the Bose amp with some RCAs (cut the RCAs and solder them in) and run RCAs to your sub amp as normal.