How should i install my tweeters?

i have a 4 channel alpine amp powering 4 jl audio 6.5's and 2 tweeters. i want to install another set of tweeters. they say they have an in-line crossover so i'm uming i don't need to purchase a crossover. my initial tweeters are connected to the front door speakers, so i'm guessing i wire the new set to the back two speakers. is this correct or does anyone have any suggestions about how i should hook them up.