Late reply (I'm a newbie), but I have a couple of VAG group cars with the 1.4 DOHC engines. A 2011
Seat Ibiza ST and a 2000 Polo. I bought the Seat having had a good experience with the Polo, so chose it to rationalize my oil and oil filter stock.
I bought the Polo three years ago, with only 25,000 miles on it, a poor service history, and
no record of it having had a replacement cam belt or water pump. It was an elderly relative's car, and, while I offered more, he insisted I pay him £250. I was paranoid for a few months, about the chances of cam belt failure, but it didn't happen. I had a few jobs that affected its roadworthiness to perform before I got to the cam belt swap, and some tools to buy. The task of swapping the belts and water pump is not at all bad on the Polo, but needs a good long breaker bar to achieve the torque to get to the 90 degree angle setting after the initial torque.
You'd need ramps, torque wrench, long breaker, crankshaft pulley holding tool, engine support bracket (I got mine from Germany for £35) I used to fabricate them for VL Churchill, and I couldn't compete with that price... and, of course, camshaft pulley holding tool, or a couple of 8mm drills (tape over the sharp ends to avoid lacerating yourself!) or bits of silver steel.
I was unwilling to spend the thick end of £500 having a cam belt changed on a car that cost only £250, so I gambled on performing the task myself. I have done a few before on other marques, though. Volvo Austin SOHC engines, Vauxhall DOHC, I took a long time on that, the first VAG one, but next time, I'll just get on with it, instead of dithering and agonizing. I've never been able to find a manual for the Mk5 Ibizas, but, being Polo based, with belt driven cams, I'll use the Polo manual for guidance if I still have the
Ibiza when the time comes for its cam belt change. The parts for the cam belt / water pump swap came in at substantially less than £100, including the necessary crankshaft screw (a stretch bolt) There are engine bracket stretch bolts which ought to be changed, too, for fear of subsequent failure.
I'd perhaps
not have risked the cam belt change on a higher value car, though, I have to admit, but £500 on a £250 car?
While I'd counsel not to be
too paranoid about cam belt change intervals whether in terms of miles or years, (see how long my Polo belts survived), but I would also say that the Seat will have higher lift cams than my Polo, so the belts (two) will be working a little harder. The other thing is that I once had a cambelt fail on a 1987 Ford Orion when it was only 11 months old, with 11,000 miles on it, and cost (Ford) £1,100 to fix, the garage told me, an experience that often comes to mind at these times.
Best of luck.