drop down menus and iframes

I'm in the process of redesigning my site http://www.rapidcars.com I want to use drop down menus for the navigation so when a user highlights the make of a car the models for that make will show up with a link to info on that car. The way I have it setup now is a scrollable iframe with text links to each car like this:

http://www.rapidcars.com/index2.shtml

. If I use the drop down menu, it stays inside of the iframe instead of going over the Iframe so it won't work for cars with long names. An example can be seen here:

Is there anyway to make a drop down menu go across an iframe or is there any other way to do what I'm trying to do? My other option is to just leave the menu all the way to the left like on the above page but I don't think that will look good since you will need to scroll down to see the entire list.

Thanks