After much research, this weekend I had a test drive in a manual and an auto Audi A3 Sportback 1.4 TFSI SE 150 CoD and have ordered a new S Tronic version with start/stop. I've been looking for a second hand one for a while and couldn't get the spec I wanted for the right price so I used carwow.co.uk and drivethedeal.com to find out the best price on the internet and used that as bargaining tool! Managed to get £2,500 off list price plus a few extras so now waiting for May/June to collect it. They've even given me a higher Part-ex value than I was hoping for the FR-V.
I've gone back to petrol after 11 years of diesel ownership for a number of reasons - I'm only driving about 7,500 miles a year now, I wanted to steer clear of DPF's and the petrol version was cheaper (about £1400 less than equivalent diesel).
The one I've gone for has Cylinder on Demand technology. "Capable of making a near seamless switch between two cylinder and four cylinder operation in as little as 13 milliseconds, the advanced new petrol-powered models can cruise ultra-frugally, but also immediately draw on 150bhp when required, so despite their dramatic economy gains they remain very much on the pace."
Official combined fuel economy figure is 58.9mpg.
This will also be my first auto and although ultimately I may lose a bit of mpg compared to a manual in a hypermiler's hands I'm hoping it will make for a much easier drive in the traffic I encounter on my commute home and my left knee won't give me as much trouble

On my test drive in the S Tronic when I lifted off the accelerator it automatically dropped out of gear into a cruise mode and a display showed it was running in 2-cylinder mode - nice!
It will look similar to this one I drove but my wheels are 16" not 17" as I wanted a more comfortable ride than the Sport and a quieter ride than the S-Line: