[Greasemonkey] HTML injection CSS clashes

[Johan Sundström]

This problem class is common to all HTML injection user scripts,
especially those that inject to pages anywhere on the web rather than
only a specific "known environment": how do we overrun styles
specified by the target web site?

I have a few user scripts that add "subscribe to RSS/Atom/RDF feed"
links for all feeds listed for autodetection anywhere on the web (for
a busload of web feed readers). They all add a little panel at the
bottom left portion of the screen, and for most pages it looks rather
good, whereas for some pages that do whacky things in their CSS, the
page styles for any CSS attribute I have not set myself, or not set
with as high CSS priority as theirs, overtakes my own styles, and
breaks layout in hideous ways.

http://ecmanaut.blogspot.com/2005/11/subscribe-to-feed-user-scripts.html

Has anyone done anything creative to address this problem from a user
script (or tooling up GreaseMonkey core for the use case) yet?

--
 / Johan Sundström, http://ecmanaut.blogspot.com/