Magpie you are alright since yours is a petrol if my brain hasn't stopped working, it's for diesel emissions, reduces NOx emissions. It cost about a £1 too £2 per litre looking at the net.
The wiki says it's safe to handle, the Ateca manual says, no. I would go with what the side of the bottle says
https://en.m.wikipedia.org/wiki/Diesel_exhaust_fluid
The chemistry of how it's used is in the wiki.
The Ateca AdBlue tank can take 12lites, minimum amount than can be filled is 5.7 litres. Page 280 manual. They recommend you don't do it yoursel but VW dealer said you could and give you a bottle with the Tiguan to start you off. Same filling cap. It is a service top up fluid but may run down between services.
This German article seems to say AdBlue isn't used in front wheel drive but that could be inaccurate.
https://translate.google.co.uk/translate?hl=en&sl=de&u=http://www.auto-news.de/test/einzeltest/anzeige_Seat-Ateca-mit-1.4-TSI-und-190-PS-Diesel-im-Test-Guenstig,-kurz-und-gut_id_38502&prev=search
It cites 1 litres does 1,000 kms but there is a read out like a petrol one which shows consumption. 8,000 miles per re fill is shown elsewhere.
The manual
vwts.ru/pps/pps_seat_163_seat_ateca_eng.pdf
Shows the order of warning as follows (usefull manual on technical stuff)
Filling level warning sequence:
/ As of 2400 km: the white warning lamp is activated. The warning is repeated every 400 km or 8 hours. OPERATING RANGE WARNING INDICATOR The remaining operating range warnings cover information about the minimum and maximum amounts for refilling. The minimum amount is used to change the indication after refilling. The maximum amount is useful for choosing a suitable refilling container. FILLING LEVEL WARNING INDICATOR Warnings for insufficient filling level of the Adblue tank warn the driver of the need to refill it. If these warnings are not heeded, start-up will be blocked when the remaining operating range runs out. In this case, once the ignition has been switched off, it will not be possible to restart the engine.
/ As of 1,000 km: the yellow warning lamp is activated every 100 km or 4 hours.
/ As of 200 km: the yellow warning lamp is activated every 20 km. / At 0 km: the red warning lamp is activated, together with the "Start disabled" warning.
The pamphlet shows the screen display. Basically AdBlue is cheap but fiddly plus corrosive.
The YouTube video shows a VW car being filled within the boot but using the screw the bottle on option. You can ignore the last big since the Ateca provides read out.
Another article says buy it on Amazon it's cheaper. Best to check the 1.6TDI uses it Ghiggz. Think it's like oil you need to keep some with you since it will need topping up between services if you do more than 8,000 miles per year. If you are on a road trip you may need it at some point.
Yes if you look on Amazon there is a trick where you buy a small bottle to get the unlocking device contained in the bottle, then a big bottle covered in this comment to fill - bearing in mind Seat say it's not nice stuff to come into contact with. Like that 15 minute was of skin and eyes.
It does what it says on the tin bit its tiny. Most vehicles require around 5 litres minimum so it could get expensive! The best method is to use this then cut the bottom off and use it as a funnel as you need the special filler mouth on these bottles to 'unlock' the tank. Then you can pay under £20 for 5 litres of the stuff from then on.
However if you are unsure or think you could be prone to spilling it you may be better off just buying multiples of these as there is no spillage at all.
Have to put that product in my private wishlist.
Another video which shows the two ways of topping up adblue, third way is to cut the bottle and top up with a big one. Reckon it's best to invest in the pipe / valve and use a 10 litre bottle, second way. The small bottles are pricey, 1.5 bottle with fitting valve costs the same as a 10 litre without fitting valve. Reading suggests use only the pipe designed for the bottle, keep to the same manufacturer. Think before holidays you just give it a good topping up. Shelf life isn't suppose to be good. 6 months in a "vented bottle".
A PDF from one of the manufacturers
http://www.halfords.com/wcsstore/libraries/document/AdBluebooklet.pdf
If it's like screen wash and you pay your owner services best to get a 10 litres bottle, the matching dosage pipe from Amazon or eBay and do it yourself. My considered view, bottle cutting and slopping it around on your new paint work isn't a good idea.