Thanks fellas.
You're right Gareth, I've only had the car for 3 weeks and still learning about it - also it's my first Audi! I'm used to working on marques like Alfa Romeo, Subaru, Saab and the Peugeot 406 Coupe. I think I need to spend more time on the A5 to familiarise myself with it.
I have access to a well equipped workshop and will be changing the transmission fluid next week. Whilst the A5 is on the lift I'll have a longer look for where the brake pad wear warning wiring would plug in. And also at Dalswinton's suggestion check for brake pad wiring at the rear
With best regards