I have seen frooglesim's video of the PMDG 777 during the day, and when the lights on the wings are on, it reflects off the ground. This isn't the case for me as it only does this at night. How can I get the lights to reflect off the ground during the day too? I will post a link to the video to demonstrate what I'm referring to:

 

 

Scroll to about 0:30 second mark and you will see the lights clearly reflecting off the ground during the day.

"Splashes in daylight" is the option I think you're after.  It's in Simulation options, page 5/6.