I want to get some gauges for my max, so i can keep an eye on vitals. Question is, how are most of these installed? i.e. water temp gauge(the mechanical or electrical) do u tap into an exisiting electrical line or drill a hole? And for the oil pressure gauge, do u have to divert oil from a line? another thing, where are u guys puttin ur gauges, i know some of u have A-Pillar mounted gauges, but i'd like to put them into a holder and put them under my headunit...anyone done this before?