https://www.traillink.com/trail/cape-cod-rail-trail/
The point to point trail is an entirely paved bike path/rail trail that is 27.5 miles in length and is almost entirely flat, with about 700’ of elevation over the 27.5 miles. The largest “hills” are the over passes heading over the major roads. I see no advantage to starting on either end, so I propose there is only one FKT for the route.
North Ridge of Lone Pine Peak is a mostly 4th Class scramble with some 5.4-5.5 crux sections. Car to car starting track from the Meysan Lakes Trailhead.
The North Arete route ascends 800' of rock, 4th Class with some 5.7-5.8 cruxes. The FKT is Car to Car, starting the track at the Mosquito Flat Trailhead, Climb the North Arete, descend the normal descent route and back to the car.
Richard Goodwin Trail from East Lyme to East Haddam, approximately 13.5 miles. The trail has easy parking on both ends, and consists of a mixture typical southern New England terrain - pine forests, mud, open fields, and rocks. Bring your bug spray and a map, the trail is often buggy and can be hard to follow and was recently re-routed in several locations.
http://www.eightmileriver.org/wp-content/uploads/2017/07/TrailPlan_20170421_D.pdf