[mickmate]

Some have no roll bar to attach them to (street cars). It's all about position of the belt anchoring points relative to your height, spine angle etc. Bottom line is they need to be mounted so if they have to restrain you it doesn't compress you at the same time. Research it carefully it's an important safety consideration. SCCA and NHRA rulebooks are a good source of info and any new harness should come with all the info you need.