Looks really good, making it go long will help too. Have you thought about tilting the forward most panel forward to match the angle of the back glass? It isn't that big a deal, but would look better for sure. Pay attention to whether the back glass bows out a bit as it does on my 2000 GMC Sierra, that was an "Aw Heck" moment when the topper I made was touching on spot on the back glass. Here's a pic to see what I mean.
Even in the picture it's tough to see, but the glass is closer to the bed in the middle than on the sides.