The old "analog input" entry from the inputs menu is gone, it was broken for a very long time anyway.
It's something inherited from the dos days when Warlock tried to add some very primitive handling for analog inputs for some racing games. I never took the time to test this properly and make a good sdl version since then... Now it's done.
For now the new system is added to git for chasehq driver (so it's the chasehq games + night striker). The principle : a dipswitch determines if you want the analog input for the steering wheel, the accelerator and the brake. If you don't it's the usual analog inputs as always.
If you do, and a joystick axis is associated to this particular input in the controls, it uses this axis value for the analog input.
The left & right trigger in the recent game pads are seen also as joystick axis, so if you associate say right trigger to accelerate and left trigger to brake, you get some working analog inputs for both.
I didn't check with a real steering wheel, but it should also work, the steering wheels on pc return axis values.
The only drawback is that if you ask in the dipswitch some analog input and the input associated has no axis, it will just be ignored and you won't get any input at all for this one, but I guess it will become obvious in this case !