I recently got a a pretty high quality and healthy frozen turkey at .99 a lb, but I only had two hours to cook an 18lb bird. I remembered once in my late twenties hearing a roommate of mine explain how to cook a turkey faster, without drying out the breast or under cooking the legs, one had to expose the legs more and the breast less. And this also makes for more crispy skin and easier carving. I did a quick search and it turns out the technique has a name. It's called "Spatchcocking."
I tried it. I needed to use a tin snips since I didn't have a poultry knife, but I washed it very well first!
I added a quarter of an unsqueezed lemon and apple under each breast and leg. I always think this helps the drippings taste a little brighter. I sometimes use just lemon, or orange, etc. Then I rubbed with high heat canola oil, and shook on some salt, pepper and a little Old Bay seasoning.
It was great, and quick. Here's some recipes
Serious Eats.com: How to Cook a Spatchcocked Turkey: The Fastest, Easiest Thanksgiving Turkey
New York Times recipe: Fastest Roast Turkey
Real Simple.com, cut a Turkey in parts