I'm 6'4" mostly legs. Knees hit keys, can't see any oncoming traffic from passenger side due to rear view mirror. Something had to be done.

Phase 1 (current): I have a solid 1" drop. Cutting the seat pan as shown allows it to drop down farther between the rails. Removing the motor and mech for the rear seat pan height adjustment and the sensor for the fore/aft slider memory (rivets) makes room for it to drop. Pan is definitely more flexible, but keeping all 4 corner mounting bolts with the height adjustment mechanism locked at lowest position, seems to provide enough support - like a stretcher, not cantilevered. Slight reroute of the main fat wiring harness that forces the seat pan up about 1/2" on it's own but it's on the inside edge of the seat and not very visible.

Phase 2 (possible): Another 1" is viable with more aggressive cutting at the back of the seat pan and welding in some additional support to stiffen it back up. You won't be using the rear 2 bolts, so the post-cutting flexibility would be a problem without it. Also need to cut the lever off that rear height adjustment rod so it doesn't stick you in the bum (where the motor drive attaches). It's all about that big transverse rod. Phase 1 overcame the limits imposed by the motor and drive mechs range of motion, and phase 2 removing the bolts will get around the static binding of the 3 part hinges between that rod and seat pan as it nears it's lowest position (preventing it). Once welded for support, the pan can just lie on that rod in it's lowest position, and proper fabrication of that rear edge of the pan will let it sit lower on the rod as well (without feeling it in your bum).

I feel much better now! This may be good enough for me as is, but good to know I have some additional options that will certainly do the trick if necessary.

You can see the big gap between the back and the base now of course, but I don't feel it. It makes me happy to see it.


Before and after cut.

Gappy

See how the removed material lets the pan clear the rails to go lower.

Removing the fore/aft memory sensor

don't burn your upholstery with the angle grinder

 

Well done! I too am 6’4” but mostly torso. Knees touch the keys, but I can live with that.

Fortunately, we’ve got a convertible, so sight lines are decent. I’m assuming your struggles are due to having a coupe?

Cheers to you for this project! And cheers to the rest of the big folks who have to squeeze into these beauties. Worth it.

 

Mine's actually convertible too which does help a lot - looking at stop lights over the window etc. But I still feel like I'm going to get t-boned every time I pull out - the mirror kills me. My plan C backup is actually to remove the mirror and put a suction cup mounted on low on the window below my line of site. So yeah - definitely worth it! We'll make it work somehow.

 

Just a note for anyone desperate enough to try this for some extra headroom....

Removing the fore-aft position sensor (pic below) does raise a airbag warning light. But that sensor only engages in the forward 1/2 or 2/3 of travel - I assume it's to adjust the airbag response if you're sitting very close to the wheel. Since it's only me driving and the whole point is legroom, that will never happen. So luckily simply plugging that sensor back in, unmounted, and just taping it out of the way on the bottom of the seat addressed the issue for me. Was a nice quick fix, as I assumed I broke some sensor or wire when the light came on after re-assembly!


Removing the fore/aft memory sensor