I saw that BOGOF offer, it's still a rip off.
If you bought standard it was £4.99 for 5l, but 2 for one so £5 for 10l
I found their concentrated stuff, 1l for £2.99, mix at 1 part to 20 parts water, so £2.99 for 20l.
Seems the ready mix is paying for water!
not sure on cost, but i'm guessing its all the same stuff as has log o for each franchise in the vag family.
not sure part number an dno chance of going out as it's freezing