LEEXUSis300

What does everyone think about adding an SUB and AMP(sub) to the factory is300 system? I'll prolly run signal through the high end of my rear speaker. and have the sub in a box right at the opening of the rear arm rest thing. Is there a way to cut out low freq to my factory mids and highs, and just have my sub running the bass? thanks for the help thomas lee 2003 yeyo white is300

What do you guys think about adding an AMP and SUB in box to my factory system. I would run the high end out of my rear speaker to the SUB amp. I'd have my sub right at the opening of the rear set armrest thing. Thanks for the help. Is there a way to cut out the low freq to my mids and highs and just have bass comign through the sub