Visual Warning from TRAMP when working in a sudo:ed context.

[Nordlöw]

Emacs TRAMP is *the* solution when a system UNIX administrator
temporarily needs superuser privilegies. One feature I am however
lacking as default is that Emacs visually somehow warns me when I am
working in a sudo:ed context typically in dired or when I am editing a
file under /etc. Does such a feature or option already exists? If so I
do I activate it?

One useful example would be to highlight the statusbar background in
red or perhaps even better add some text statusbar at the top of the
window.

Thanks in advance,
Nordlöw