My fabia did not come with heated seats and I quite fancy adding these. Is most of the wiring already present in the loom or is it a case of getting loads of new wiring. I cant seem to find an exact answer in the search panel but that could just be me.

You'll need to add the heated pads and controllers into the seats,  and then get the loom below.

 

You'll also need the dash switches.

 

http://www.kufatec.co.uk/shop/en/skoda/fabia/fabia/seat-heating-harness-skoda-fabia

 

I have a pair of the genuine switches if you wanted them.

 

http://www.briskoda.net/forums/topic/331296-mk1-fabia-parts-parcel-shelf-net-heated-seat-switches-radio-fascia/

Best having a read through this as well:

 

http://www.briskoda.net/forums/topic/321510-heated-seats-with-kufatec-loom/

Thanks for the replies