Two crappy iPhone pics, but you get the idea. Ignore the dirty car and the soon-to-be-replaced-by-CS7s filthy 17" wheels. I coded out the cold and warm bulb checks and I have no errors and no flickering or otherwise undesirable behavior.
The MTEC kit I got is BMW-specific and uses a relay system to power the ballasts rather than the headlight wiring. The wiring harness also has two additional features connected to each ballast - a "control box" and a "rectifier" - but I'm unsure whether the coding changes I made or the fancy wiring harness are the cause of no errors. Either way, I'm a happy camper and I'm more comfortable knowing that there is a relay system powering the HIDs rather than the headlight wiring.
One note to add about the HID kit. In the interest of wanting to maintain an OE look and have the highest lumens possible, I stuck with an OE-like 4500k for the kit. Unfortunately, these are quite white and have zero hint of blue; definitely more yellow than OE HIDs are. My guess is that these are actually closer to the 3700k range than the advertised 4500k. Side-by-side with any factory HID setup, mine look almost like standard halogen bulbs in terms of the Kelvin rating. Put mine next to a typical halogen setup, however, and they look less yellow and more white. Point being, they still are whiter than halogen lights, but not as white/blue as factory HID setups. The manufacturer sells replacement HID bulbs and I may pick up a set of 6000k to see how they look.
The T5 LEDs lighting up the angel eyes use 2 side-firing high-power SMDs each. I carefully installed them so that the LEDs were pointing sideways in the mount, thereby projecting their light through the circumference of the ring, rather than at the center and outside edge. This combination of using only side-firing LEDs and careful alignment in the mounting holes all but eliminates the four hotspots that are typical of the Depo AEs. Note, I ordered 5000k LEDs because the Depo AEs already have a slight blue tint to them. At night, these definitely have a blue hue to them (definitely more blue than the HIDs) and in hindsight, I might have gone for the seller's 4000k offering, but I'm still very pleased with the results. Since changing the LEDs requires pulling the headlights out, I'll stick with these until one happens to burn out, if that occurs. Speaking of which, the eBay auction included 20 T5 LEDs. Nice to have as a backup in case one or more fail.
Speaking of the AEs, I also coded my car to run them as DRLs. Now, these aren't even close to being as bright as the late-model E92/E93 LED AEs, but they are still noticeable during the day and I think they add a nice modern BMW character to the front of the car during the day.
MTEC HID kit