Knock Link then, far cheaper but in my eyes no where near as accurate. My matesin his Subaru would go mad all the time yet I he told me that was "normal" If the last light is blinking then surely thats bad IMO and if its ok then how long can it flash for before its not ok ? The Phormula setup is a lot more accurate and you dont have to buy that full kit, they start at under £200 for the actual incar unit and sensor