Daylight is fine, but darkness isn't to be frowned at. If you have LEDs, that is.
For an odd project I cheaply bought fifty 10mm White LEDs some time ago, and I have used exactly...one, so far. I got me that RC car recently, and it's fun to play with during the day.
Now there is also fun to be had in the dark (Yes I am a solitary geek, why do you ask?).
Cutting the Lexan was tedious, glueing the foam blocks messy and far from a perfect solution, but the initial mockup looked as if it would work ok.
The cheapie LEDs didn't come with any tech info, so a bit of trial and error resolved that 30mA is sufficient and that they are happy with just under 3V. The Wheely King's ESC has a battery eliminator output of 6V, and I soldered up four LEDs as two parallel pairs of two each in series. The multimeter showed about 47mA for this setup, and I decided that the voltage match is close enough to forego any limiter resistors.
The cheap mounting results in a fair bit of light leaking under the car, which is actually useful and looks "cool" anyway :-) Driving the rc car in the dark is loads of fun, and the light output is really nice. The BEC is crappy: on motor engagement it apparently provides more voltage, the LEDs light up stronger, but on full throttle they occasionally go out altogether (I'd think the voltage falls below 5.5V or so, and the series-connected LEDs go below the threshold). But regardless of the non-constant light this is fun, if a bit "riced up".
Taking photos in the dark isn't, and I couldn't be bothered to rig a tripot. And of course with the flash on you don't see any lights...