Don't know if it'll help, but I have this plan for when I get around to fitting my new carpet:
1. Fit front section, only slitting around seat track mounts and trimming edges around kick panels and sill plates when sure it's centered and fitting well.
2. Mark the center of the trans tunnel at the front and rear of the front section of carpet.
3. Remove from car and cut into left and right halves at those marks, to be joined later by Velcro, which I'll stitch to the cut edges (have to refine that detail, as carpet won't have an overlap).
4. Refit both halves of carpet.
5. Fit console bracket, trimming carpet locally round it and the shifter cutout.
6. Test fit the console, and only trim edges of carpet over tunnel as required to get console to sit low and level.