Yeah tons of previous recommendations on the board. Some of our favorites are Hebert Brothers Seafood and Beach Pea Baking in Kittery, York's Best (on Route 1 between York and Ogunquit) for Fried Clams, Beach Plum Lobster and Sundaes at the Beach in Wells, Scratch Bakery in South Portland (if you're headed out to Two Lights Lobster Shack on Cape Elizabeth), Toots ice Cream in Yarmouth and Thomaston Grocery near Rockland for Amy's Blueberry Pie (call ahead and reserve one). .
I don't know if I'd "drive up the coast" to Bar Harbor, however, unless you mean you're stopping here and there for the night. Route 1 up from the border doesn't really hug the coast, you have to veer off onto the peninsula roads to see the coast, and that takes some real time. "A drive up the coast" from Mass to Bar Harbor is a helluva long day without much time to stop and enjoy the chow. Might be better to plan a freeway drive up, and ask about short chow detours off the main drag.
Sundaes at the Beach
231 Post Road, Wells, ME
South Portland, ME, South Portland, ME
225 Two Lights Rd, Cape Elizabeth, ME 04107
Treat's Bakery on Rt 1 Wiscasset Maine has large and small pies that will blow your socks off, plus lots of more treats.... What a wonderful market, and almost across the street from Reds......
I stopped last summer and got a 4-berry pie, and I thought it puts all others including my mothers to shame............