I\'m currently using ASP.NET MVC 4 CSS/JavaScript Optimizer. It works good with my own CSS/JavaScript, but I also want to use it with plugins. Each plugin has its own folder
Might have a look at RequestReduce. It's another .net based minifier/bundler and it will rewrite all urls in the minified/bundled css to be absolute. This includes fonts and background images. It will also automatically expand any imports in the css. Additionally, where it thinks it can, it will sprite the background images.