I'm very interested in your experience. I've been thinking about Silverstars vs. PIAA in my 400E. I really don't want to do the Euro light changeover (price, hassle, losing the headlight wipers). Seems I've read elsewhere on this forum that the W124s (i.e. with 9004 bulbs) didn't seem to get that much benefit from swithing to PIAAs. I'm glad to hear you've had good luck with them!