I put on some driving lights and fog lights because at night I totalled one car with a deer (deer warning horns don't work) and one van with a moose (thank-you, Ralph Nader, for airbags - I would vote for you if I lived there).
Unlike most cars, the Fit's headlights (but not park lights) are positive grounded so the wiring has to be different from that indicated on the instructions. The relay has to be wired differently as does the switch (if illuminated). If your switch is illuminated by LED's, then you will probably have to completely rewire the switch because of the positive grounding since LED's are diodes which only let electricity flow in one direction.
Driving lights must only come on with the high beam head lights. Canada has daytime running lights (DRL's) which use the high beam filament at a reduced voltage. I found some circuit diagrams on the web - but they were too complicated for me. So I tried connected the relay for the driving light to the DRL module instead of the high beam - thankfully this guess worked (I was expecting smoke). It prevents the driving lights from coming on when only the DRL's are on.
The fog lights should only come on with the low-beam headlights.
Initially I wired the lights incorrectly so that the high beam and driving lights (55W) and fog lights (55W) were all on simultaneously. I didn't think the Fit's weak system could handle all those watts, but it seemed to be OK for the short time that all three sets of lights were on.
Both lights are fastened to the metal bumper to minimize vibration.
I'm frequently on gravel roads so to protect them from rocks, I covered the driving lights with clear Lamin-X and the fog lights with yellow Lamin-X. So far the lights haven't been broken. I wish I had just used clear Lamin-X for the fog lights as well because in the autumn, the grass in the ditch is yellow and I think a clear light would provide more contrast if an animal were to jump out.
My wife was pretty upset when she saw the Visa statement for the lights. She said the Fit already has good lights. But yesterday after she drove 400 miles at night, she mentioned how good the lights were

.
The fog lights are those little yellow things at the bottom - they are suprisingly effective in spite of their size. I bought these because they were cheaper than Honda's and because I wasn't sure if Honda's fog lights could be adjusted horizontally.
I was pretty proud of the driving lights but the first day my wife drives my daughter to school all the guys were smirking - which embarrassed my daughter to no end. I guess the lights look totally uncool.