Closest: the meters by the Capitol bldg (catacorner to Sanger), but I believe they're two-hour parking, so you'll probably get ticketed if you leave your car there all day. I've also heard M2s suggest interviewees park in the patient parking areas -- but don't get caught or you'll look like a douche on your interview day!
Best: probably the street at the Bottom (i.e., east of Broad and 17th) or at your hotel and get a taxi
Also, I would suggest giving them a call to see what the status of interviews is for tomorrow, since the University closed today by order of the Governor. Who knows what tomorrow ill bring. (We are hoping for another closure and consequent delay of our practical....)