Bad news! - the cable arrived yesterday and it doesn't work.
2 issues with it, firstly its a very tight fit, the aux/usb connectors in the
Ibiza are at right angles to each other so ideally you you need an "L" shaped Aux connector so it won't get in the way of the usb lead. The connectos on the Ford cable are both straight - so it's very difficult to plug both the usb and aux cables in.
Secondly, when I did eventually get both cables plugged in, nothing happend, the iPod showed no signs of charging or anything and selecting Aux/USB on the head unit just displayed "no media".
I tired it with 3 different iPods, a 2nd gen iPod touch, a 5th gen iPod video, and a 2nd gen iPod nano so it's nothing do with the iPod touch requiring 5 volt power or anything like that since I tried a broad spread of iPods.
Shame it doesn't work - but theres obviously more to the SEAT cable that goes some way to justifying it's £65 cost - oh and if anyone is interested SERE motors sell it for £57
I'm not sure what to do now: buy a 16 or 32gig memory stick - or buy the SEAT iPod dock/lead.