I took an A4 Avant 140Tdi out today at work as they have them as the 'Poole' cars which we take out if we need to go to suppliers etc. This is the first A4 i have driven, it was a 140TDi Avant Diesel and i thought it was horrid!!! The interior was not bad but lacked alot of features that the S-Line A3's have, one thing i was suprised it didn't have was the trip computer, i am guessing its an optional extra yeah? Even when warm the engine rattled loads and was VERY loud! I am sure the A3 diesel wasn't this bad when i test drove one. I could feel the engine rattling through the pedals and when i was waiting to come out of junction i rev'd the engine and i could feel the engine rocking the car!!!! I am soooooo glad i didn't go for the diesel engine in the A3. Quite dissapointed with the A4 even though it costs loads more than the A3!