Help a wanna be newbie going too look at an S4 please

[Audidoody]

Hi, going to look at a facelift S4 auto Monday or Tuesday - please tellne where the chassis numbers are ? Plus any typical S4 auto issues to look out for would be most appreciated.
Thanks

[HYFR]

chassis number is printed in the engine bay, just under the batter cover....will be staring right at you