How to customize page title?

[a1ex07]

Hi guys,
I want to append a string to a category title, but I cannot find what I should change.
Let's say I have a category "cars", and I want the page look

 <title>cars - extra text</title>

The text is dynamic, so changing category name is not an option.

Thanks for you help.

[a1ex07]

I ended up with modifying "html_header.php", not sure if it's the right way to do, but it seems to work for my needs. I think another alternative is to change "meta_tags.php"