the white plug is called a smart harness...
made by metra.
the other end of it should be the factory harness.
you can either remove it....or just cut off the white part...then match up speaker wire colors... thatd make it easy for you.
metra made those harnesses for circuit city. so that the installers didnt have to actually wire a harness....you bought the car side harness with this connector. then you could buy a brand specific harness that would connect using this white harness. if you chose not to buy the brand specific (sony, pioneer, jvc...etc) then youd still buy the same "smart" harness for the car...and cut off the white harness.
you may wanna research this site thou.....ive given good clues on the best way to install a radio. the bugs dash is a little tight for some radios...esp with the way the harness gets in the way, and if you have a usb connection coming out the back or have rcas for an amp.....so getting one in is sometimes a bit of a struggle.
ive never had an issue with the k line...but ive never worked on your year specifically.
so check on that...
but most likely its already been done....since someone else alread had an aftermarket radio in there. wiring will be easy...as long as whats there isnt messed up for some reason.
either find a smart harness for your brand radio and plug it right into that white harness....or cut it off and splice in your radios harness....
good luck