welcome to the forums...
If you are willing to make the modifications, you can fit them in there. They probably wont fit behind the factory grill. You will have to cut a hole in the kickpanel and mount them form the outside. Check your speakers for depth first. It wont look stock but being down in the floor it wont be very noticable.
-There are 10 kinds of people. Those who understand binary, and those who do not.
-If we ever forget that we are One Nation Under God, then we will be a nation gone under...Ronald Reagan