Hey Rob,
Just few Qs:
Does the beam level adjustment dial, next to the light switch in the car, still work with this mod?
Yes the level adjustment still works as the existing dipped reflectors are being replace with bixenon projectors so all 'back of house' remains.
Does the 'one tap three flash' also still work with this mod?
In all honesty I don't know as I've not heard of this before however I don't see why not as the existing high beam remain as mentioned above.
What is the life expectancy for these? I presume once leds start dying the whole unit will need replacing as you can't swap them out like the standard headlamps?!
As with most LEDs the life expectancy is 20000-50000 hours....your looking at 12-24 years if driving for 4 hours every day!...probably last longer than the rest of the car!...but as you say if one failed it would need a replacement led strip etc.
Cheers my man