Wow, a girl thats like cars (especially 2002's)!!!!! Most are like my stupid sister. Daddy, daddy fix my crappy truck. Daddy daddy, why doesn't this work.... i think you can figure out the rest!!!
Anyways, what to look for:
How many owners, how many miles, what does the underneeth look like? Is there rust anywhere? What is the condition of the interior/extierior? Pretty much just examine the entire car. Especially the electrical system. Older German cars tend to have crappy electronics (i know from expierience). And check out the VIN number on carfax.com. And if you think you ready to buy it, take it to a mechanic to check everything out.
Just remember to always think about how much time and money you really want to spend on it. hope this helps. If you have any other questions, just let me know and i'll try to help out!