Hello all. I recently purchased a 1995 GMC S15 Jimmy (4-door) with OEM stereo and speakers. I am in the process of replacing all the Delco components with aftermarket audio. The OEM speaker wiring has me confused though. There are 6.5" speakers in all four doors with small tweeters front left/right in the dash. The front and rear door speakers on each side share the same colored speaker wire, brown and yellow on left and light blue and dark blue on right. Why would GM use the same wires for both front and rear speakers? Thanks.