I am not an IMG, but I think it's great that you are applying to programs in the States. I think all American programs could benefit from some IMGs.
I think this is the trick to matching into strong American residencies. Letters from clinical rotations at strong schools in the States help, and support from research faculty at strong schools in the States help. There are some superb matches of IMGs in the States at the top-ranked residencies, not only in medicine, but in specialty fields, but most of these people have done research for people in these programs for a year or two, so they are known entities, and they have support of professors with known names in the field.
This is probably not much help now, but in case you are delaying your match for a residency that you love, I hope you realize that there are opportunities for foreign grads in even the top-ranked programs in the States. Brigham, MGH, UCSF, Stanford, Penn, Cornell, Beth Israel-Deaconess -- all of them are willing to consider foreign grads if they have support from internal professors.
It takes a bit more effort, but if you want to stay in the States or even if you don't, there are opportunities for foreign grads at the top programs here. There will always be favoritism for American grads, even though a lot of us are not as good as you are, but that will probably always apply to each country (we would also struggle if we were applying out of country).
Best of luck to you.