If your B8 A5 has the red "warning" lamps in the trailing edges of the doors, then most of the wiring is there, since the entry lamp (AKA puddle light) is wired in parallel with the red warming lamp, which is powered from the door control module (possibly VAG PN 8T0959793J). Best case, the entry lamp connector harness is there; worse case, you'll need to get a couple connectors with pigtail wires to make this work (search aliexpress.com for "vw 893971632"), possibly wired to the door control module directly (e.g., ETKA doesn't show the lamp connectors in the A5 door wiring harness in '09); these are powered by terminal 16 of the 32-pin door control module connector. --g