fixed width page, categories and currencies help

http://nonelectronics.com/catalog/

I'm seeking a way to push the categories and currencies boxes on the left outside of the white background area.

I could do this a number of ways. I''m thinking the best way would be to increase the size of my #maincontentwrapper from 760 to 890 (my left column is 130px,) and keep the background on those boxes transparent. My question is, how do I expand my maincontentwrapper LEFT instead of just having it expand both ways?

Right now it's positioned by doing a

margin-left: auto;
margin-right: auto;
and setting the width to 760 in my stylesheet.

When you state "push outside" do you want these to be in the grey area at the left?

Exactly!

I can increase the size of the mainwrapper by 130px and make the position relative then move it left 65px, which is half of my 130px left column....

that'd work, I think, but I'm sure there must be a more elegant solution out there.