've made some changes to the stylesheet to expand the nav bars the full width of the site. I did this by modifying the #MainWrapper to 1300px. As you can see there are a couple of issues:
This is not a good idea. For customers with smaller monitors/lower resolutions it will create a scroll bar on the bottom for the site. If you want the navMainWrapper to use 100% of the page width without creating a scroll bar, you should move it outside of the fixed width div and then make the width 100% for the navMainWrapper. Here is a good tutorial:

http://www.w3schools.com/css/default.asphttp://www.w3schools.com/css/default.asp