I didn't have to bash or modify the tunnel of my S15 at all. The set up I used was pro tuner adaptor plate, stock S15 flywheel and clutch, 370z CD008 gearbox, gearbox moulding pour points ground off to give clearance on tunnel, chopped and shortened 370z gear lever bracket, custom prop made by prop shop uk after sending them s15 and 350Z prop with measurements, 350Z clutch slave cylinder simple solid mount plate for gearbox mount. As long as you're happy to grind off the cast moulding points on the gearbox housing it will fit in the tunnel quite nicely, can even tidy up the bottom of the box so it is all flush and smooth. I've previously fitted CD006 and CD009 boxes but for some reason the 09 boxes pull a premium compared to the others and after opening them all up I'm happy to go with the less popular ones, just as tough, and strange when the 370Z,s over here are running the older gearboxes from factory, the biggest annoyance is the locating dowels being different diameters between models but an easy thing to modify.