Hi all, Im thinking about upgrading my audio systeem. I have the Premium sound with sat nav at the moment. Right now im quite satisfied with the sound, but the front door speakers do not deliver any base at all. So i was thinking about upgrading them. I would like to know if the front speakers are 6.5 inch or 5 inch one's. Because i've read about both so now i don't know for sure which one to look for. Im not intending to use a aftermarket amp or anything like that. I would be happy if the base would be a bit more then now. To replace the speakers, can i do it by taking of the speaker grill? Regarding tweeters: I'm ok with the stock one. So in short i would like to know: What size speakers do i need? Are they easy to replace? Is it worth upgrading? Some suggestions... Thanks in advance guys.