Remember, enthusiasm isn't just acting the effervescence and bouncing up and down in your chair. This sounds like an opportunity, for both us. I'm sure we could work well together. By that is meant responding with interest to what the interviewer is saying and asking important questions. List to overviews.
Overviews are a rich garden of material for questions.
After the interview, if you are accepted, you will be placed in a position not knowing exactly what you will be working on unless you ask questions. Questions can become the most dynamic part of an interview. You can ask questions which help align your goals with the job. You can use questions to establish rapport. You can ask questions to take the focus away from you.