Time to buy a Jerry can perhaps? Pays off very quickly using say PetrolSpy's graph if you time the pricing cycle...I got it .. but it is always $50 minimum spend, and my car has a 27 L fuel tank so ...
(not that I'm asking for >$2/L fuel again!)
Regularly refilling our cars with fuel (when hit 25% full) priced 25 cents (or more) per litre cheaper. Best saving was 62 cents/litre x 20 x 2 Jerry cans.