Xenon HID Headlight Lamp Replacement
Buyer beware. I looked online to find a replacement Xenon bulb for my 2016 Cascada and found that Philips D3S was listed everywhere. I picked the best price and ordered one.
I waited about six weeks for a cool Saturday and removed the existing bulb. I was amazed that the windshield wiper tube could be removed to make room for your hand to fit. It was a still a struggle to get the bulb out and I couldn't get the new one to fit. I compared the two bulbs and noticed the D3S was missing a keying slot. After further investigation I noticed the part number on the old bulb was D1S and when looking it up on line the picture matched the original bulb.
I waited to long and cannot send back the D3S for a refund but the correct one cost half as much.
By the way, the left headlamp hadn't been working for 7 weeks, the car hadn't been driven for 4 hours, and the base of the old bulb was very hot to the touch.
The lesson here is to look before you leap.