Tail light assembly nuts

I was replacing bulbs in my tail light assembly and one of the retainer nuts fell into the body of the car. Do you know if replacements can be purchased or what is the size needed for a regular nut? It is a 2013 Elantra.

Thanks

 

I would call up the service dept and ask if they know and if they sell it
Otherwise, got to other side tail light and check that retainer nut
And go to auto parts store ... ask for help

Sorry, don't know every nut and bolt of every car produced

 

His question was more of "what size" than what would someone do...looking for same answer and so many threads give the same obvious advice, not an answer, which is only reply WORTH posting.

 

If you, DoIYourslef, know then please by all means tell us what size nut it was and where to purchase it.
Otherwise your post is as good as mine.