There is no Haynes manual for it so maybe try looking for a Haynes manual for Volkswagen, something along the lines of the Jetta model, as the Toledo's engine is made by Volkswagen and the its size it roughly the same as a Jetta, you maybe able to download one free if you get the right site or possible order for Amazon.co.uk usually for a third of the price as Halford's or somewhere like that, good luck anyway!
All you need do is go to a Seat dealer, who will then get the code for your car from the manufactures
SEAT LEON HEAD BOLTS ARE ACTUALLY KNOWN AS CAMSHAFT HOUSING BOLTS{IF THIS ENGINE IS THE SAME AS IN MY 2002 1.4 LEON S} THE BOLTS SHOULD BE REPLACED WITH NEW ONES AND TORQUED TO10Nm+1/4turn(90degrees)further. TIGHTEN FROM CENTRE OUTWARDS USING CROSS-OVER SEQUENCE
Signo has electric windows + mirrors.
somewhere in the car :) on my seat toldedo 1999 the OBD key is hiding behing a small plastic cover, located in the storage space under the centre console ashtray, right at the back, prise the plastic cover and the OBD is underneath