I just thought of something that may save you a headache or two. Our cars use two bulbs that are hard to find. The front parking lights (in with the high beams) are "H6W" and I had to resort to buying them from the DEALER for $13 EACH (!) but you can get them from this site
(PowerBulbs.com H6W bulbs) - I ordered some last night we'll see how it goes, they have to come from ENGLAND! The other bulb is not quite as hard but AutoZone and Advanced auto parts don't always stock them - it's the H7 headlight bulb, I ordered some from Powerbulbs, too. I bought some "Cool Blue" bulbs at Advanced, they look really good, not too blue just clean, white and noticeably brighter than stock; however they both burned out after about six months, FWIW. Their replacements have fared better, so far so good.
HTH,
-Tom
P.S. I think I just found these H6W bulbs at Fastlane (the link at the top of the page) they are under the "Tools and Hardware" section for the 96 E320; part number is Y4001-69893: Halogen Bulb 12V : 6W $3.13 . DOH!