Hi all,
I want to share a relatively new product. You just hook this up with no extra power wires. It will add about 100w per channel. You could mount these anywhere. Heck even inside the old big ballon speaker pods. Replace the speakers and now you have upgraded your system without any complex wires with a decent power increase.
Rockford Fosgste PM100x1 - they are sold in Pairs. One for each channel. ( Price Range $325-$399 US )