you can install as many lights as you want, as long as they're total wattage is under 55 watts
the wal-mart fog lights and new 25 watt landscaping bulbs in each are popular
i bought a set of regular halogen "rectangular" foglights from advanced auto, and have one on my sons, and slickerthanyou split the $20 cost with me and runs the other one on his sons, into their second season now