What's it called--the panel your heels hit

["Richard H. Overman" <sunset_village@compuserve.com>]

Does anybody know the correct name for the panel in the rear seat that your
heels hit if you are sitting back there?  Mine has holes for heat to come
out.  It is so rusty that it swings back and forth...so I am looking at
junk yards for a better one, but what is it called?