Hello folks - looking for clarification as I embark on replacing headlight bulbs on 2006 G35 4D sedan.

First - for a few years I've had the passenger side headlight sporadically crap out now and then. Hit a bump, would go out. Hit another bump the next day, come back on. Or even just start the car the next day, would come back on. Over time it slowly got more frequent. Now I'm pretty sure the bulb is entirely out. Would like to replace (will plan on replacing both).

Don't need anything fancy - just looking for OEM or similar replacement from local store or Amazon/online parts.

But I'm confused as to what I'm seeing. From Infinitiparts, I'm seeing part number 26297-9B90A. This seems to be listed as "D2R" type bulb? What does type D2R mean?

I ask because while shopping on Amazon, I'm noticing that Amazon suggests this part 26297-9B90A, D2R, does NOT fit my 2006 G35. I realize that Amazon is not the be-all end-all authority on what will fit what, but I'm assuming they are tapping into some auto parts database that would know.

Amazon DOES seem to think that an aftermarket D2S version WILL fit my car. (I can't figure out how to include a link in these posts).

So in short, what is the difference between D2S and D2R?

Oh - and also does anyone know what the OEM bulb color temperature is? There seem to be a choice among things like 4300K, 6000K, 8000K. I know 4300 is warmer, just don't know how warm it is. My headlight (hi/lo) bulbs are definitely cooler than what I'm assuming are halogen fog lights on this car.

Thanks much!
Brad in MA

Okay - I do see one website that lists the 26297-9B90A as "D2R". But I'm thinking that's incorrect. I'm thinking I need a D2S bulb for this 2006 G35 sedan. And 9003 for foglights.

But before I go through all of this, I'm curious if there are typical culprits I should be aware of that may be causing the light to work sporadically. How typical does the ballast and/or igniter cable fail? What else? I know anything is possible, but any tips in diagnosing this greatly appreciated. aka why do I have the feeling that a new bulb may not solve my once sporadic (now permanently out) light problem.

Thanks!