I chose the telescopic ramp because I sometimes have to park my Jeep in a tight space, and my large ageing Rottweiler's arthritis makes it impossible for her to jump into the back. At full extension the ramp is perfect for her, and apart from needing a bit of encouragement, she uses it well. It is rather steep for her when not fully extended, but is still much easier than trying to jump in, and the rough surface means there is no chance of her slipping once she is on it. It just about fits in the boot when the dog isn't with us, and comfortably fits on the back seat when she is, but storing it might be difficult if you have passengers on the back seat and a large dog in the boot. It is a bit more expensive than some of the others, but I think it is money well spent.