Adam: Congratulations on a very sharp and tasteful 300E.
For others wanting to do the HID-thing, another consideration may be the new Catz Zeta lighting system at under $300. They promise 170% increase in light output!

Not a true HID system, though.
About eBay...I've been watching a couple of auctions for clear front corner lights for the W124. They are posted by Internet dealers and, when you check out their sites, the prices are lower there then what they sell for on eBay! Go figure.