Dr Pepper and Guinness are not drinks you would normally associate together, but what distinction do they share?

Well, this seems like a rather tenuous shared "distinction," but it's the only one I've been able to come up with: Guinness is brewed in Dublin, Ireland, and the oldest Dr. Pepper bottling company is located in Dublin, Texas. (It's one of the few that continues to use cane sugar.) Perhaps someone else can do better on this than I managed to do.

The question conjured up the absolutely disgusting possibility that someone might mix Guinness and Dr. Pepper. Let's hope no one actually does that.




https://en.wikipedia.org/wiki/Dublin_Dr_Pepper

You're quite correct Frankie, Dublin is the connection but the distinction they share is that they are the oldest brewery and bottling plant for their product.
I don't actually know what Dr Pepper tastes like, but Guinness apparently does mix with some strange drinks. Guinness and champagne make a Black Velvet, and I knew a girl who used to add blackcurrant cordial to hers.