Purchased a 2015 Nissan Murano Platinum with the Bose sound system. First area lacking is the subs. It appears from my research there are 2 x 5 1/4" 4 ohm subs in the spare tire well based on the research I have done. I however cannot find power handling ratings. Im looking for recommendations to replace these subs with something a little more refined. I will probably continue to use the factory amp and install locations to keep everything as stock as possible.