That was one of my main theories way back in the beginning...........still is. She may have known someone right there in the complex and ran up (or over) to their apartment after pulling in and parking. This could be someone she met out by the pool one day or something. The other residents living there may not even realize these two people know each other. And therein lies the entire problem, you have a suspect that nobody suspects. It's been my theory since day one that this may well have been pulled off by someone living right there in the same complex. Based on the known circumstances, that theory would actually make the most sense.
Then we have AtomicAngela on post #263 stating that she spoke with another resident in that general area and that person didn't even know someone was missing - i.e., she wasn't interviewed by LE. It may be someone no one else is aware of. But then again, there may be that one person who remembers a pool party or gathering, but if LE doesn't talk to the residents they won't find it. To use that sports quote from Wayne Gretzky, "You miss 100% of the shots you don't take."