I embarked on a little project recently. One of the bulbs for the corona rings ("angel eyes") went out on my wife's 2011 E90 328i, so I investigated replacing it myself. I can obviously have the dealer do it, especially since it's under warranty, but I thought I'd look into the procedure to see if it was something easy I might want to try. Turns out that the bulbs can only be easily accessed from the wheel wells with the plastic inner fender liner removed, so I decided to just let the dealer take care of it.
But while I was doing the research, I also looked into replacing the low and high beam H7 halogen bulbs. We took delivery of this car from dealer inventory last Spring, and it didn't come equipped with xenons. The difference in the quality of light thrown by my M3's xenons and the 328's halogens is staggering. I really wanted to improve the lighting on the 328, and I found good reviews on the Osram Rallye 65w H7 bulbs as replacements. I read the DIY for replacing the low beams over on e90post, and also consulted the owner's manual. I ordered the Osrams online and got them a few days ago, then set about installing them yesterday.
Kiemyester's diy thread on the low beams was very helpful. I turned the wheels sharp to the right to get to the driver's-side access panel in the front of the inner wheel well liner. With a well-placed magnetic light I was able to see well enough to remove the protective cover, disconnect the power supply plug, and release the securing clip to remove the stock H7 bulb. Putting in the replacement Osram was straightforward. Same process was repeated for the other side.
The high beams, though, were a different story. What was BMW thinking? The high beams are too far toward the midline of the car to be accessed from the inner fender access panel. The owner's manual suggests that you instead access the high beams from the engine compartment. But even though you can manage to open the protective cover, you can't directly see the power supply plug or securing clip for the high beam bulbs. You have to try to manipulate the connector and clip blindly, in a very tight space. Unless you have a dental mirror and elf-like hands, you're out of luck. I had neither, so I decided to remove the wheel in hopes of seeing more towards the center of the car through the wheel well access panel. My view was a bit better, but still not adequate. So at this point, an hour later and thoroughly frustrated, I removed the entire forward section of the plastic inner fender liner. Aha!
Now I could see! At this point it was very easy and straightforward to replace the high beam bulbs, just as it had been with the lows. In fact, it was easier because I had wide-open access. The only difference was that the high beam bulbs are oriented with the metal tab down instead of up as they are with the low beam bulbs. Ironically, at this point I could have easily replaced the dead corona-ring bulb since I had free access through the fender, but of course I hadn't ordered a replacement bulb since I planned on having the dealer do it.
After reinstalling the fender liners and wheels, a test run showed that the replacement halogens are quite a bit brighter, especially the high beams. Overall a worthwhile project. Relatively inexpensive, but obviously labor intensive. No pics because I didn't think of it at the time, and also because it wouldn't add much more to kiemyester's excellent diy thread.
Again, BMW, why torture your dedicated customers?