It’s the DEF injector. Completely normal - nothing to worry about.
I thought for a second you'd bought a new one.Welcome to the forum. Hope you have great luck with your diesel. I have a 15 ctd with 51k and it’s been a great car so far.
I have looked and driven a 17 Diesel, happy with what I have and driving a lot. It seems like a better decision to just drive what I have and enjoy. If I stop driving so much, I may look at something else.I thought for a second you'd bought a new one.