How to use a static map with a responsive theme

I’m trying to get a full width static map on my responsive themed site. I can easily get a normal dynamic map to work but when I change it to static it defaults to its ‘minimum’ width size. I can set the width manually using pixel size but it doesn’t work using using a percentage. It appears that there’s no problem generating the static image but the dynamic width size is not getting through.

Is this a limitation of the plugin or a fundamental problem with static maps?

You can see a susefful implimentation of a dynamic map on my site here
I have been trying to using the template code as follows
`echo GeoMashup::map(‘static=true&height=200&width=100%’)

https://www.ads-software.com/plugins/geo-mashup/