Hi BEM systems were fitted from 2004 on most models except on some entry level A2s and have to be coded, if it was fitted by Halfords it should have been coded except at the two local Halfords in my area when I enquired about my daughters Q3they were perfectly happy to sell us a battery and fit it for an extra £20 but when I enquired about coding they went a bit sheepish and said we don't have the equipment to do that, buyer beware.