As it happens I was speaking to an ex Audi technician last week and he was saying about DPF, apparently 3k on motorway for 3-5miles should clear it out, I don't know how true that is, strumbled on the topic in new posts and just thought I'd add to it 
Cheers for this. Yes, handbook says 70km/h in 4th for 5 miles.
Problem I've got is that I got in the car this morning and drive out of the garage (hadn't been drive since light came on last night). Got to end of (short) drive and noticed that the light wasn't on! Hasn't come back on after 30 miles of driving today either.

Rang the garage this PM - haven't been able to book in as their systems are down but they have all the details and will ring me tomorrow - probably will be with them for a full day then back again when the part they need is on back order
