Re: Stubborn Tar
Best is McGuire's Wheel Cleaner (alloy-safe) and the McGuire Rim Brush (soft tipped). Spray on (< 1 min), scrub, hose off. Can clean 4 wheels in 5 mins, assuming you have 5-spoke design. The brush will not scratch your alloy wheels.
Those who visited the Esso station wash on Steven's Road will realise that they used their own concoction - but equally powerful in removing dust and tar.
Could be Mama Lemon or some washing powder (washing detergents for clothes are meant to dissolve oil-products).....