Dave cad

Hey guys, Sorry to be that guy but I'm looking for some good guidance when buying, I've always owned Japanese, last car was a my98 impreza t2000, so I'm not too confident looking round a4s. I've got the basics like dpf, oil pump problems and servicing schedules but is there anything else that I should be looking/listening for? I'm told that the cr170 and 140s are pretty bomb proof? Cheers for the help