Ever read your owner's manual?  It says your passenger must sit primly
and properly. Really. Imagine your grandmother sitting with her hands
neatly clasped in her lap. Okay, that's an exaggeration, your hands
don't need to be clasped. They can rest on top of your thighs. I get a
kick out of telling my passengers that if they sit with their arm out
the window, or even on the door's armrest, that arm can be FORCEFULLY
RIPPED CLEAN OFF THEIR BODY!!!

In case anyone doubts my statement, in MY "2004 Forester Owner's Manual"
it states, on page 1-64,

"WARNING
Do not rest your arm on either front door or its internal trim. It
could be injured in the event of SRS side airbag deployment."

Furthermore, directly above the warning is a picture warning against
sitting the way 99% of my passengers sit 99% or the time. (See also page
1-63.)

Also, on page 1-66 is a picture of a person sitting in the recommended
position. I don't know what the passenger is doing with his hands, but
let's just say, if my mother ever caught me with my hands there, she
would have made me go to confession.

Anyway, I'm not a passenger too much when I'm driving, but I think the
same thing applies to the driver's side, in a mirror image sort of
fashion. If that's the case, I think it won't be too long before my arm
is FORCEFULLY RIPPED CLEAN OFF MY BODY!!!