Sounds like that's exactly what they are doing, trying to identify where the car was before and after it was at 1122 King Road. If someone had come forward to explain why the car was at the murder scene at the time of the murders, police would have said that the car is cleared.
I wouldn't be surprised if the vehicle left the Moscow city limits, so finding which direction is the first goal. I doubt the vehicle is more than 20 miles from Moscow because it's hard to put together someone living in another state, and planning a targeted 3 AM mass murder at a student rental in Moscow. The targeted/plan fact seems to require someone who is in the area more often.
From Dec 12 transcript posted upthread:
"There's been a lot of questions about the white car that we've been interested in. We're looking for that car because we believe, through our investigation, that
that car was in the area during the time of the murders and we also believe that the occupant or occupants may have seen something. They may not know they've seen something. So, we specifically want to talk to them and we want to know who they are and what they might know or might be able to contribute to the investigation.
...
We have literally an
army of analysts who have been sorting through videos that have been submitted through the fbi.gov.moscow upload site. Those videos are from all over town, gas stations and specifically the area around King Rd. We've been trying to
use those videos to garner new information. As you can imagine, there's hours and hours and hours of videos, so it does take a lot of time."
link