For the sake of convenience, let us define free will and determinism. If it is you who determines your choices, that's free will. If it's something else, that's determinism.
Yes, I know there are a few gaps in my theory. I kind of write the whole comment in a hurry, so I'll explain a few obvious questions which arise from reading my comment.
1. How does the body know of a choice ten seconds before the choice enters our awareness?
Again, there are many things which we don't know about our body. One explanation could be that there is a time gap between us and our own senses, so by the time we become aware of a choice, our brain has already made it. Another explanation could be that our brain keeps track of everything happening, and deduces what will happen next based on the available info, having the brain realize there is a choice to be made before the mind realizes that.
2. How can it be a free will choice if it's done subconsciously?
Simple. Imagine doing anything subconsciously. Breathing, for example. You do not have to focus on your breathing to do it. You can do it subconsciously. But, even if you do it subconsciously, it is still you who does it. Same with making choices. You make your choices, whether you're aware it or not. You may say "But it's my body what chooses it, not me. How can it be a free will choice?". Again, this implies disconnection from your body. It implies that your body is merely a vehicle, and that your mind or spirit is a driver. And while that may hold true for a large number of people, the proper way of being is with the body, mind and spirit all aligned and balanced.
Those are all I can think of. If you have any questions about my theory, feel free to ask.