I have an '07 JK Wrangler (2 door) & have removed backseat for additional space. Plus it's almost impossible to get into backseat. I also have a large breed puppy. He's been riding in a crate in back....but is rapidly growing out of it. He'll be approximately 110 lbs. Looking for suggestions in keeping him safe while riding. (Other than buying a bigger Jeep ;-) Can a dog safety harness be attached anywhere?