Ok so I have told my son in-law he could use the 5ver I just bought if he installed a hitch, he has a crew cab and short box gmc, I did mention to him he might need a slide (but I really didn't know exactly why) from what I am learning is the back of the cab is too close to the center line of the rear axle so when you turn sharp (beyond 40 deg?) crunch, by sliding the hitch back although not good for general towing, you can get in and out of those tight spots ??? Is that the basics ?? and if your lucky can go beyond 45 deg??