Strange rattle in front passager side

I have a rattle in front passager side. It does it mostly when its cold and idling = sometimes it goes away..

 

Inside? Outside?

 

Yeah we need a little more info.

 

Its a long shot with the minimal info you supplied but I just fixed a similar rattle when in those conditions. It was the stock intake rattling against the inner fender well. The isolation foam wore down and a vibration could be heard in the cab when I warmed the truck up in the mornings, but vanished when i was in gear.

 

Another long shot, but I had what I thought was a rattle behind my radio. Turns out it was an extra light bulb rattling around in my glove box.....

Easy to check at least.