Hi guys ive been working on a 02 fabia for a while and ive been trying to add speakers to the rear. Im struggling with the wiring since the car didnt come with wiring for the rear of the car. Is there any way i can add the wiring and somehow attach it to my stereo? I have a aftermarket stereo that came when i bought the car that allows rear speakers and a subwoofer.

Do you have rear passengers with you who like to listen to music? 

Otherwise there is no reason why you would want to fit rear speakers. Ive disconnected mine as they just make it sound tinny and muffled compared to just fitting a decent set of front speakers.

I really wouldn't bother if i were you

A subwoofer is a much better addition if you are upgrading your sound system, followed by the front speakers and sound proofing

I do normally have between 3 and 4 passengers when going to uni. I am planning to install a woofer once i had the funds. I have a couple of speakers ripped out of a passat lying around so i was thinking maybe i could install them. 

In which case I would get some 10cm coax speakers which mount in their positions either side of the parcel shelf. Then just run 2 core cable to each one along the sills behind the trim and around to the head unit.

They will never sound good but will provide some rear fill in sound. 

Thsnks I appreciate the help