How to search within words

The search doesn't return results for partial word results- only exact matches. For example, a search for 'cars' won't match 'car' text on the page, and a search for 'car' won't match 'cars' text on the page. The search has an issue not finding filenames like I'd expect, either. Such as file attachments with hyphens, like blue-car.pdf. A search for 'blue car' won't find it, nor a search for 'blue' or 'car'.

I see a variety of attempts of making the search better through modules, but it seems messy- nothing seems solid yet: http://drupal.org/node/103548

I want to add a simple % to either end of the search string to allow this.

Is there an easy place in the php code this can be changed without an apocalypse occurring?