i'm looking to get the rear spoiler plus the rear diffuser from Jag.....does anyone know where i can find the part numbers for these parts?

A jag main dealer now owe me a favour so they will sell me the parts no problem as i know they're not really meant to sell xkr-s parts without an xkr-s chassis number.

 

...if the dealer owes you a favor, then they should be able to look up the part numbers with no issue, I'm sure. Have you asked them?