Scratch,
Thx for the advice. It would appear that this is not an isolated incident. My service engineer let slip that another A5 which was being used for 15 minute journeys suffered a similar fate; the driver was advised to take a longer, open road route to work! The secretary of the London dealer mine ended up at volunteered that mine was the first A5 with the problem but that several A3's had been in.
My service manager has now said I should have been asked what kind of driving I did and told that the DPF is prone to blocking in city congestion-driving, resulting in ECU limp mode and a low-loader if the car isn't quickly run at 50mph+ for 20 mins. Difficult in London.. Apparently, new sales booklets are also being printed with warning information.
If it happens once more it's a money-back situation and a different model - one that works in town..
I hope that, given this could become a major problem for Audi (you can't sell a car that can't do town driving, certainly not without telling the buyer) one hopes they will find a fix.
I think it would be very useful if folks could add any similar experiences to this thread. Safety in numbers and all that..