My 2002 Silverado HD 3500 has a 6 bulb (I'm only using 4) Tomar unit in the front with amber double flash bulbs mounted at the outer corner of the headlight housing so its aimed for maximum visibility at both front and side front views,the headlight housings are APC projectors and I burred out about a 1" hole and siliconed the rubber grommet bulb assembly in, its very concealed looking and another pair is mounted in the fog lights, they flash an alternate X pattern like a pace car. The rear has two sets of two bulb units also made by Tomar, two are in the yellow lens part of the taillights and the other two are mounted in a retrofitted small oval fog lights under the rear bumper.I manage a fleet of concrete mixers so my truck doubles as a service truck. I went with Tomar because they are reliable and reportedly brighter.