LE has the vehicle, so they got quite a bit of information from the tags, registration, and possibly some evidence from inside it.
I think what they are searching/asking for now, is more detailed info from a person or persons who may have witnessed any activity involving the vehicle that day, e.g.:
- Arrival - Did you see the vehicle actually being driven? What time? What direction was it travelling in, or from direction did it turn off the road into the parking lot? Did you see the driver? Did you see the driver exit the vehicle? What did he/she do after exiting? Retrieve items from it? Walk away? In what direction? Were there any passengers in the vehicle? What did they do? Can you describe the driver and/or any other people you saw? Can you describe him/her - face, stature, gait, clothing, etc., Were there any individuals who on the ground who appeared to be waiting for the vehicle to arrive?
- Departure - same basic questions in reverse - did you see someone approach the vehicle? What time? What direction did he/ she come from? Was the person on foot? Alone or with others? Dropped off by another vehicle? Can you describe him/her - face, stature, gait, clothing, carrying items? Which way did the vehicle go when it left the lot?
I don't think LE expects to be able to find someone who saw everything there from 12-5. But, what if someone happened drive by and saw something they felt was suspicious? Or pulled in by the building to turn around and saw someone or something? LE is looking for any missing pieces that will help them possibly tie a driver to the car and/or possibly tie him/her to the crime. JMO