In my last A6 the led footwell lights remained on all the time regardless of wether the doors were open or not, you could even control the brightness via the mmi. They give a nice ambiant feel to the cabin when driving at night time.
Don't suppose anyone knows of or has heard of a mod available that will switch them permanently on in the A5???
Don't suppose anyone knows of or has heard of a mod available that will switch them permanently on in the A5???