Don't feel bad about Harley - I am still having problems with Andy. I adopted her at a year old from the breeder; at the breeder's she was either in her crate, in a dog run (where she had a "potty corner"), or out in a fenced yard.
She never potties in her crate, but she still has potty accidents over by the front door. More often, it is a pee accident - but sometimes, it's a poo. Usually she gives me enough warning for me to rush her outside before she poos on the floor.
It's frustrating, but don't give up! And don't feel like you're a failure because you're not the only one!!
