Hi, Looking into buying a 520D mainly for commuting (2008 with 100k miles - has full service history with BMW garage) - this is with a main dealer and comes with the 2 year BMW warranty. I have never owned a BMW before and choosing between this and Audi (A4 - I know should be comparing against A6 but prefer the A4)

just a couple of rookie questions ..

Is it better to pay the extra (about 2 to 3k) to buy from main dealer and get the warranty ?
What is the performance and handling like in comparison to Audi A4?

any words of advise before I buy?

Thanks for any advice - really appreciate it !