using a H.I.D bulb in any assembly not designed for them will have glare, just some are worse then others. I did the conversion on my 5th gen the light was good but had so much glare had to aim them down to not blind oncoming traffic but after 4 months finally did the retrofit with S2k projectors and after pulling the bumper off 6 times and 2 headlight assemblies latter trying to get them aimed properly , oh what a night and day diffrence the light patern is even with prefect cutoff so i'm blinding oncoming traffic well worth it!

as for fleabay kits if you get one with good ballist like hellas and a name brand bulb like philips,osran it's the same O.E.M quality D2R ,D2S bulb put into a base that fits your light housing. one good thing about hella/bmw ballist is they are small and can fit in tight engine bays.