Latest update, the A4 has gone back. Very disappointing but the right thing to do.
With more knowledge about the running costs (repairs!) of the TDI ultra engine I'm mulling over a 1.4tfsi. In my budget I could probably pick up something around 50-60k miles and will do 15,000 mainly motorway miles each year. I don't mind the drop in economy if I can avoid an inevitable £4-5k spend on adblue/egr issues. But would love to hear any feedback about reliability specifically of this engine on higher mileage. Are there any differences in engine codes across different years from 2016 onwards? And anything to be aware of e.g. chain vs belt. Thanks for all comments and replies so far. I'm considering other VAG options too - the B8 passat has a 2.0tdi pre-2018 with no adblue which is very attractive!