youll end up melting your grill. a kid did that with his ranger around here, looked clean, its an 03 4x4 well, now he has them mounted on the front, but the stick up past the hood, looks kinda dumb, but, now hes got a 2wd grill.
I installed a couple of 55 watt lights behind the grille. Drilled holes on the plastic, which allows for about 1/8" space between the grille and light. No problems at all. Keep the wattage around 55 and you won't melt. I've had mine on for hours on end during road trips and have had no melting.