Fake five star reviews that all sound the same is such an easy pattern to spot once you start reading carefully. Look for reviews mentioning specific details like installation time, terminal cleaning, or warranty registration, those are harder to fake convincingly.
Mussafah has some genuinely solid BMW independents but the key is asking upfront if they have ISTA diagnostic software, not just a generic OBD scanner. That distinction matters a lot on these newer B48 engines.
Metal shavings on the diff drain plug means the damage is already done. Spider gears or carrier, either way you need someone who knows Dana 44 tolerances before driving it further.
Jerking and slipping on a multitronic A4 is almost never a full replacement situation. A valve body service or clutch plate fix handles this in most cases for a fraction of 11k.