A little update on this, when I originally installed my Mazdaspeed seats into my 6 I only ever got 3 bolts in on the driver side, I have fixed this.
Here is how,
I would recommend doing this before you put the bottom cushion on the seat frame.
The driver seat frame rail where the front 2 bolts go through need to be ovaled out, towards the middle of the seat about 1/4 to 1/2 inch on each side, doing this should make the front bolts line up correctly.
The mazdaspeed seats are more bolstered than the stock seats, they are a upgrade from the leather seats for sure, and they go well with the rest of the interior.