Tonite, while perusing the Internet, I heard a "snap" from one of the snap-traps. Lo and behold: I got him! Turns out it was a fairly large mouse, around 5" long body and another 7" of tail. I took him outside for his picture.
This morning, while checking all of the car's vital signs, I found him in the Lincoln engine compartment, but he quickly took off before I had a chance to do anything. I hoped he stayed in the car, so I moved the car outside immediately, and left it there. Apparently, he decided the garage was a bit more hospitable...NOT!
That's not a mouse . It's a rat.