Bob,
Typically residency interviews are in Nov-Dec-Jan of 4th year, with some dependence on which specialty you are interviewing for. For instance, anesthesia begins as early as October, and any specialty in the San Francisco match will also be earlier. So, schedule accordingly I suppose. Choose to do an easier rotation, where it will be fine to leave for days at a time, at your home institution if you cannot take all of those months off. Don't schedule an audition rotation during interviews.
I would save your away rotations for just after you finish 3rd year, you really want to be at the top of your game and it is best to have done the vast majority, if not all, rotations before auditioning. I only have 2 months left of my 3rd year and feel unbelievably more comfortable after completing each rotation. However, I think doing an "audition" rotation for me right now would still be too early as I would like to have them all completed first.
Any 4th years are welcome to correct me on any of this...