LPT Request: How to make graceful conversation with someone when you don't understand what the fuck they're talking about

My neighbor and I got into a conversation about the automatic seatbelt in my car and it ended up going to a bunch of car maintenance stuff that was way over my head and the best thing I could do is nod and say "yeah/oh yeah?" repeatedly

Edit: This is with the assumption that I do, in fact, want to continue the conversation

Edit: jesus fuck some of you sound absolutely horrible to be around