You know, I didn't think you looked like a donut-eating kind of a gal! So it's sandwiches and coffee, eh?
I've never been in a Dunkin Donut shop, so I don't know what you have to face - I guess it's all presented in a pick-me-up-easy-to-go kind of way.............
The nearest I have to it is probably Costa - I get drawn in about twice a month, because it's expensive, and the way they present stuff is SO tempting - it all looks so very desirable. Just yesterday, I celebrated Friday and the beginning of a week's vacation from work, by going in and getting myself a 'Green Tea, Lime & Mint Cooler' which was basically like a snow-cone rather than a drink! If I had more money available, I could very easily find myself heading in there for a coffee (and something to eat) more often.
Good luck with your quest to drive right on by and eat what's 'in the bag'