Upgrading the DRL with LEDs
BMW integrated the DRL bulb and holder as a single piece but you can actually “notch out” the bulb and replace it with a bayonet style (BA9S). If you want to go brighter you can experiment with a higher wattage incandescent but you run the risk of introducing too much heat. Alternatively, you can go with LEDs which results in a bulb error warning... unless you
code it out 
Plugged in my trusted OBD adapter and used Carly to disable the bulb voltage monitoring. Happy to report no errors! The LED has a nice uniform output whereas the stock DRL has a dull spot at 12 o'clock. Also keep in mind LED's run much cooler so don't read too much into the "50W equivalent" descriptions. In reality these LEDs use less than 5W but for brightness go by lumens. Pics below are factory vs 6000K vs 6500K.
I actually prefer the blue during the day as it washes out less. But at night the white looks cleaner. And with regards to the turn signals, I've never been fond of the orange so I swapped in 6000K bulbs in there too which results in a softer yellow for the signals and full white for the corner.