Fuel tank sending unit, $173 at ********


http://www.**********.com/search/product.aspx?sid=rrvkde2m4ud03enapylfzin0&makeid=800016@Mercedes&modelid=1356364@E320&year=1999&cid=22@Fuel%20%26%20Air%20System&gid=3331@Fuel%20Tank%20Sender%20(For%20Gas%20Gauge)

Easily accessible from inside the trunk!