Ctrl-I: AI control of player car.
Ctrl-T: switch to trackside cameras.
[ ]: decrease/increase FOV.
F1: display developer menu.
BACKSPACE: goes back a level in F1 menu.
Ctrl-P: cycle to next post processing filter.
Ctrl-Shift-P: switch post processing filters off.
Ctrl-F: free camera.
Ctrl-S: display FPS.
W,A,S,D: move seat
TAB: cycle lap info
Ctrl-+ & -: Full damage/repair damage of car
Ctrl-Alt-+ & -: Full damage/repair damage of all cars

Camera Edit Mode (Build 159+)

To enter the mode you press Ctrl-K.
Then the following keys become active:

Numpad 2: increase pitch
Numpad 8: decrease pitch
Numpad 4: increase yaw
Numpad 6: decrease yaw
Numpad 7: increase radius
Numpad 9: decrease radius
Numpad 1: increase roll
Numpad 3: decrease roll
Numpad -: increase FOV
Numpad +: decrease FOV
D: forward
A: backward
W: up
S: down
Q: left
E: right
SHIFT key in combination with any of the above: slow down camera movement
Numpad 5: reset to original settings for current camera

Custom DOF mode:

F3: on/off
F4: reset

Focus plane distance:
F5: decrease
F6: increase

Sharp field depth:
F7: decrease
F8: increase

Transit to blur depth:
Shift + F7: decrease
Shift + F8: increase

Blur:
Shift + F5: decrease
Shift + F6: increase