Another solution without you having to manually mess around with the Unicode characters can be found in Making Font Awesome awesome - Using icons without i-tags (disclaimer: I wrote this article).
In a nutshell, you can create a new class like this:
.icon::before {
display: inline-block;
margin-right: .5em;
font: normal normal normal 14px/1 FontAwesome;
font-size: inherit;
text-rendering: auto;
-webkit-font-smoothing: antialiased;
-moz-osx-font-smoothing: grayscale;
transform: translate(0, 0);
}
And then use it with any icon, for example:
<a class="icon fa-car" href="#">This is a link</a>