you might get by using the wires you see at the bottom of the woofer in the trunk. but those are not the only wires feeding the speaker. that is just the low frequency, the high frequency go to the tweeter via seperate wires. the yellow wires are positive and the red are negative, i know, goes against common sense. feed a line output converter audio control lc2i, check it out. i just purchased a used 07 camry se with the JBL premium 8 speaker system. 6 speakers, 8 different drivers. replacing the speakers is not as simple as it sounds. you must remove the back seat to get the rear panel out, along with the the side pillar covers. this is just the beginning of the problems. the rear jbl speakers are component, with the crossover points done in the under seat amp. i do not know the xover frequencies. the 6 disc changer jbl head unit uses serial bus digital signals to feed the amp. so adding an aftermarket amp is a chore. you will need a line ouput converter, audio control ls6i or similar. this converts the post amp speaker signal to an rca preout signal to feed a sub amp and main amps. i stole the signal from the rear speaker wires while i had the seat out. the jbl amp feeds the rear speakers a high frequency to the tweeters and a low frequency to the woofers. took a while to figure out what was what with that issue. no prints or anything on line without paying $. i fed the left and right high signals to input 1 and the lows to input 2 of the lc6i. used the signal summing to get a full range signal to feed my amps. to just replace the speakers is a gamble , betting on the sound will be good with jbl amp xover setting to match your new speakers, which would have to be component, not coaxial. to just add a subwoofer, as i was only intending on doing, is a major task for an amature. luckily i am an audiophile geek with tins of electrical experience. use critical mass ss69 6x9 speakers, and the xover frequencies of the jbl amp will match very well with these speakers, if you don't want to add good amps and such. these speakers are coaxial but are biwire or biamp capable, i got a set on ebay for 160$. long story short, go all out or just stay stock, or replace everything stock and loose all the goodies like aux input, steering wheel controls, bluetooth
, and all that. it is all ran by the jbl system. GOOD LUCK!!!!!!!
jbl factory head unit 6 disc changer, nice piece!
audio control lc6i line output converter (magic little box made it all happen)
jl 500/1 amp on a jl 10w6v2 sub
precision power ppi 4240 4x30amp
critical mass ss69 rear speakers
focal 165 k2 6 1/2 component front speakers
and a million dollars worth of wiring and goodies
AWSOME SOUNDING SYSTEM