I may finally have an answer to the AUQ question
Just been round our forecourt and checked the pumps on 03 LC, 53 LC and 54 LCR
All 3 cars have the following part number fitted 8L0919051B (after checking this part number it superseeds to 8L0919051H, so from that i can only assume all AUQ's are fitted with a 4 bar pump from the factory)
Robbie
Not sure if will
help but the OE pump is a VDO and the other number i found stamped on it was 228 233 016 002, i'm guessing this is possibly the VDO part number