Interesting case. Stabbing is so up close and personal. An argument? Drunken brawl? Did the victim have cash to rent a place and robbery was the motive?
The car and newspaper seem to be good clues. With the owner having relocated to Colorado from OK, the victim could be from either place. The car had not been transferred if it had been sold, but doesn't mean much. Some people don't bother to change the title until the tags are overdue. What else was found inside the car? Cigarette butts? Trash? Maps? Anything in the glove box or trunk? Was the driver's seat pushed back to accommodate a man of 6' to 6'2"? Rear view mirror and side mirrors checked for height of driver?
The real estate section for Sparks, NV is a logical place to have started the search. If places were circled, he could have already called the owners/agents to set up appointments and exchanged information. At least, this would have given a timeline when he was in Sparks. What was the date on the newspaper? Sparks, if I recall correctly, is largely a blue-collar town. I could see him being a blue-collar type without dental insurance. Transients don't usually go house hunting. What type of dwelling was he researching? Unless he was looking for fully furnished housing, he would have something with him. Was it in a storage facility? A trailer pulled behind the car? He didn't have a suitcase or anything found with him or the car so it could indicate he had a place to stay.
I found a multi-colored moving pad/blanket which could have been purchased at Walmart:
http://www.lulusoso.com/upload/20120403/multi_color_moving_pads.jpg
Is this close to the pad/blanket found at the scene? What else was on the pad/blanket besides paint? Were there spots of blood to coincide with the tool markings found on the skeletal remains? Other bodily fluids? Did it appear he was first buried inside the pad/blanket? He was not wearing the jeans, but I find it strange they were inside the pad/blanket. (If he was only wearing underwear and a t-shirt, a jealous husband comes to mind.)
If the crime scene is not the dump site, he had a reason to move and hide the body because it could somehow give him away. The dump site is in quite a remote location except for the small "community" north of the road leading to the body. Unless someone had help or lived nearby, he would have found it difficult to dump the car. Sparks, NV is nearly 2 hours away and Lake Tahoe appears to be over an hour. It is reasonable to think the victim had been to both places. But if he was killed in either place, there are closer places to hide bodies and cars.
The phone calls are intriguing. Why go to all the trouble of hiding the car and body only to call and give them up later? The killer would have no reason to do so. Either people came across them randomly and didn't want to get involved or perhaps a 2nd person was involved in dumping the body and car.
The dog does seem to have been associated with the victim. It is in a dog's nature to stay close to the master's body. Some dogs refuse to leave, but others will try to alert people and travel back. The collar could actually have been torn by the dog in an effort to get away from a tie out (but where was the rope or leash? And why tie up the dog there anyway?). Dogs will rub against things or they will sometimes find a way to stretch out the collar to get it in their mouth to chew apart. Why take the dog out to the dump site if the victim was killed someplace else? Makes no sense why the dog was there. Could the man have been killed close to the dump site so the dog just found him by scent? (The little "community" nearby becomes even more interesting.)