Description Reviews Magnacor Spark Plug Wires come in 8.5mm (Red) or 8mm (Blue) and will work on Gen 1 Cooper or Cooper S's. They will give your electrical system a bump in performance to complement all your other performance mods, or are a good replacement to replace your worn out stock ones. There is not much of a difference in performance between the 8.5mm (Red) or 8mm (Blue), so pick the color that best complements your engine bays color scheme. 1 Review 5 Nice clean wires Posted by Joe on 29th Mar 2015 These wires are extremely flexible, feel very solid and perform as they should. They are very short and clean under the bonnet, no excess length to have to route around. As we all know, Red = Racecar! Solid upgrade from stock wires.