I was thinking of installing a Rockford Fosgate PBR 300X2 amp and connecting it to only the front speakers and replacing the front speakers only. This way I could stay with the 2 ohm system. My goal is to keep the cost down but still be able to hear music at highway speeds. Opinions on this approach? Also - with all that I've been reading about flashing the HU what exactly is does that mean and how is it done?