May be store specific but Wilkinson in Scarborough are doing 1 L of Antifreeze for just 2p.
It is labelled up as 75% off but when you get to the till it comes through at 99% off, reduced from £2.39 per litre to 2p.
I bought one as a standby for next winter thinking it would be about 70p but when I saw how much it scanned at I went back and got another 3.
Still plenty left in store as of Saturday afternoon.
Definitely not online but could be in a store near you.