I do remember someone mentioning an abandoned white truck in Texas, but I believe it was more along I-10, near Beaumont? I'll try to find the post.
San Jacinto county, honestly, would be an easy place to hide something. A large majority of it (80%?) is right in the middle of the Sam Houston National Forest. I've been up in that forest and in other areas of that county quite a bit in the last 2 months and, let me tell you, it's woodsy and sparsely populated. Small towns scattered about, and then lots of expansive (and I mean expansive) farms and ranches. It'd be quite easy to burn out a truck and not have anyone notice it immediately. There's a lot of trash burning up there, so a fire in and of itself wouldn't be suspicious and unless someone came upon the burning truck while it was burning, it would go unnoticed for a while.
All that being said, it would be really hard to get back to Houston, where you could take a bus or a train back to Lafayette from that area. Anyone know if he had a motorcycle or something he could have brought with him and used that to get back? And there's always the real possibility that someone he knew helped him. If the truck was right off of the 59 portion of San Jacinto County, I could see the hitchhiking theory, maybe. But if in the middle of the forest (there are farms/ranches in there, it's not just an undeveloped forest)? It'd be pretty difficult to pull off, and going out there with no definitive way to get back would be pretty risky.