Awesome upgrade to my shaker 500 system. The 6x8 factory speakers were made in Mexico, can't believe Ford didn't put better quality in a Gt! Love the new sound, can hear all the highs and lows and plenty of bass. Cost me 140 installed!
Kickers are a solid low to mid price range speaker, I personally think they are a little tinny compared to the polk speakers. But speaker upgrades are always a good idea not many auto manufactures use anything better than paper or cardboard for the stock speakers. Remember they are auto manufactures not speaker manufactures.
Soon you will be adding an amp and sub to round out the low end.
Well I ended up going with kenwood excelon 6x8 all the way around only to match the kenwood excelon deck and My bass shaker is 2 12' kickers found out after I bought the kickers the kicker box it came with wont fit in my trunk its kinda depressing if I want bass I will not have a back seat cause thats where they sit....