You guys nailed it- the starter went bad. Kudos to my hometown BMW dealership. They sent a flatbed to grab my car and took care of things quickly. Coincidentally, it was time for my X3 to be serviced, so the transport to the dealership and a new starter together with my routine service only cost me my $50 deductible under the CPO warranty.
With just over 62k miles, I was a little surprised the starter went bad already. But there could be an explanation; the service department told me that their records showed a Miami BMW mechanic had performed work on my X3's starter before. Apparently, after the previous work, the starter was not installed properly- the service department said it was installed "backward", though I'm not sure how that could be.
Thanks for your advice! Hope this helps someone else down the road.
Last edited by rletson; 11-17-2012 at 12:09 PM.