Jay
Hey guys, did you hear about Something Awful?
Posts: 8,804
I completed it, as most of chat knows.
Don't do it.
The part where you have to drive in a car is a *****. Basically, you have to drive in a straight line or else the gnome clips out of the car. However, if you drive in a straight line, you will die by the helicopter. Especially if you drive slow.
It takes a few tries (By a few, I mean 20 reloads), until I figured out a better way is just to launch the gnome, drive up to it, get out, launch it again, drive up, get out, and so on.
EDIT: Now that I've read your post, you don't have to do it again. You just have to press activate when you put the gnome in the door. I forgot to do that on my first time, so I played through the rest of the game, hoping it was after the rocket launched and it was endgame. Still didn't do it, so I went back to that save point and closed the door, and it registered.
EDIT 2; You didn't have to take the gnome down the tunnels, you could have left it with Alex and the Vortigauns