05 Coupe Headlight Issue
 

So, passenger side headlight (HID) in 05 G35 Coupe flickers randomly. Turn headlights off and back on, magically passenger side headlight works. Few seconds later, goes out. Click headlight switch to parking lights or off, then back on, works again. Have no idea why. I checked the fuse, checked the connection, both fine. Just replaced battery. Any ideas?

What he said. Switch the bulbs from side to side and see if the problem follows the bulb. If not switch the ballasts side to side for the same test. You'll quickly find out what's causing the flickering, my bet is on the bulb starting to fail.

Doesn't anyone do a search anymore. This issue has been addressed so many times.
OP has a almost fourteen year old vehicle.
Most parts are already well past their useful life.
Time to replace both headlight bulbs and ballasts

Telcoman