I just received my Nexus 4 dock from Monoprice, bought on a bit of a whim, since the N4 and the Skyrocket are almost identical in dimensions, and it works perfectly with the Skyrocket. I tried it naked, with a CaseMate Barely There case, and a generic TPU case and they all work perfectly with no modifications. The one I bought is this one.
I'm guessing the car mount from them would probably work as well, but I can't guarantee it.
Thought this might help someone.