Which S4 to buy?

[Sherlock1965]

Hi guys

Im currently an Audi A7 driver looking to buy an S4 Avant but not sure which model and year came with the improved sport differential set up.

Im looking to spend up to approx £30k and would really welcome any help and clarification?

Thanks in advance

[Fishermandan]

I know the sport diff is an (expensive) option on the current model so I assume you just need to check when searching for used... unless you mean the more gentle torque-vectoring that comes as standard on the current model?....