Door speaker wiring..... 91 fox hatch

well this is what you can do, find the door speaker wires, if you had premium sound your front speakers are wired in Parrelle (which is fine to just hook up b/c all modern amps can handle a 2 ohm load on stereo no problem.)
Your Right fronts will be (W/LG){white/light green} and (DG/O){dark green/Orange}
Your Left fronts will be (LB/W){Light blue/ white}and (O/LG){orange/Light green}


and if you didnt have premium sound just Am/Fm, you will need to run wires to the door, and again its ok to run your fronts in parralle, if i were you i would buy a cheap set of inline bass blockers and put those in line to your dash speakers b/c your door speakers will be able to take more power w/o distorting.
IMO

yes running the door speaker and the dash speaker on the same (+) and (-) line