Sometimes the issue is so simple you miss it by assumption,
Audi a4 b6 1.8t engine cutting out with loss of all electrical power happens randomly, this issue ran me around a bit with no fault codes present on any scans related to its actual cause it was all down to a single 10mm bolt on the positive battery terminal fuse box shorting out the whole car, hope this solution to my problem helps someone else in the same position
sorry for filming in portrait didn't think about it till it was too late,
