It still irks me that I spent $80 for a small piece of molded plastic with a really basic pair of wheels and a strap. But it appeared to be the only stern cart that I could fit inside my Eddyline Night Hawk, so I bought it based on the photo on the website and a talk with a customer service person at Paddleboy. I actually got to see the other Paddleboy carts at an outfitter (nobody actually stocked the Molly, smart people). With the exception of the Pop Cart, they all looked like a much better design than the Molly.
Anyway,I tried using the provided strap to load the boat. It was a real struggle. There is no foot to hold the cart steady, so it tends to roll away on you. Keeping the boat on the cart with the strap seemed near impossible. Finally, I found that if I added a bungee, and then used the strap afterwards (I personally don't think the strap is doing much) and bungee the cart to the boat while holding the rear of the boat just so, it works.
Now, we start to roll it around. Going straight, it works okay on asphalt, a concrete boat ramp, and a boardwalk. The cart came loose on a turn, and again going up a small curb drop. I sent a complaint to Paddleboy, but they didn't seem much interested in satisfying a disillusioned customer.
At about $25, the Molly would be a good value, and with some design changes and better wheels, it might be a good product. In case the manufacturer reads, this post, I would have certainly appreciated a satisfaction guarantee on this purchase. There was no defects, just a design that doesn't work.