Relative links to CSS, js etc

I just finished a website. Someone at my customers company (an IT guy) said that all links should be relative ( instead of my usual setup of mysite/path/to/css ). Is this something I should bother with ? If so: should / could it be done in apache rewrite rules ?

Ask them why and how much they are willing to pay to get it resolved

Ask them for three good reasons....case closed

thanks