I was looking a the Alpine 6.5" SPC-170 for no particular reason than that I used Alpine in previous cars, different speakers though. Noticed they also have 6" SPJ-161C2 but half the price. Assume the price matches the speaker potential too. Would you match all 4 doors with same 6.5" as per stock setup? Then something with extra beef up back in the shelf, but possibly not for some time. I wasn't going to bother with the tweeters unless they came as a package deal perhaps, as some do. Are the stock ones not that good? Naturally, they aren't really meant to stand out over the others, just compliment them....listen to me talking speakers, no idea!