Luke,
I feel your pain. I had my MacBook stolen, I paid 1700 for mine at the time. I was soo upset. It was years ago, but I still feel the pain.
Don't give up man, I had nothing on mine, I had it for about 3 days and someone took it off my desk at work. I scoured ebay and CL for weeks/months... nothing ever came up.
Get this guy, keep trying the police. Give them access to the same site you have with the location information. Tell them once it moves then they'll have a good idea who did this. Who knows, maybe this guy has lots of stolen property.
I love the fact you took pictures of the cars. Keep an eye on that thing, it will move and once it does you'll get it! I think this is your best chance. Figuring out the IP usage would be useful too if you can get some help (FBI, Police, etc.). I, unfortunately, have no idea how you would go about doing that.
Just be persistent!
Good luck man! I'll be watching this thread.
Jeff.