SQ5 is amazing. Had a long drive in one a couple of months ago at a 'Q' driving event held by Essex Audi tearing around the grounds of a posh country house. We pretty much had free reign of the ground and fields set out in a rough course, and was able to take the cars out for a blast on the A12 and country roads. Noticed a bit of understeer if you booted it out of a corner on wet Tarmac or grass.
The car is just blisteringly quick and the power delivery is pure torque and grunt. 5.1 or 5.2 seconds 0-60mph I believe. Interior is business as usual, latest MMI interface is easy to use and colourful, and the interior materials are just solid and Audi-like as you'd expect. Sunroof is a nice additional too. I liked playing with the settings that changed the exhaust note, pretty cool in a diesel with Dynamic mode.
As sarg said, satnav is an option, and a pricey one indeed at £1700!
The salesman also reckoned you could easily achieve 45mpg and used prices are from around £30k at the moment. I'd love one if I could.
I hear there will also be an SQ7 released with the new Q7 line up too