I just don't know WHY

We have an old, mismatched, gas guzzling Suburban that takes 20 minutes to warm up. It's been a huge life-saver in the winter when we might not have gotten out of the driveway through the huge piles of snow if we hadn't had it. My dad sold it to us for a few hundred and we haven't gotten the title in our name as of yet.
This morning when Mike left for work it was here. This afternoon at 4:30 when Mike came home, it wasn't. Just like that. I was cleaning the house and getting ready for a family night with all of his side of the family so I was inside all day and other than running the vacuum or being in the shower, I didn't have enough noise that I would have missed that very loud engine.
It's really shaken me up that someone came on to our property and just simply TOOK a vehicle. I was here alone with my children. I was asleep from the time Mike left til about 9 am, too. After calling all friends, family, and neighbors that might have borrowed it and forgotten to tell us, Mike called the Sheriff's office. The officer came out, took our information and had Mike fill out the paperwork but told us he was holding off filing it til later tonight just in case the one person we didn't get a hold of had it.
No call yet to tell us it's found, but I'm hopeful.
The big thing - WHY? Why would someone come out to the backside of a tiny town, drive down a dirt road with 4 houses on it, turn down MY driveway and think to themselves, I should take that old 3 color Suburban with a bathtub in the back. did I forget to mention that we'd bought a tub to replace the one upstairs and since we had no room for it yet we left it in the back? Yeah.