Hi David, it was probably the simplest of all the bulbs to change, I bought Osram bulbs from Amazon, not the cheapest but i guessed they may last longer than unbranded bulbs? Some of the bulbs were really difficult to change, the worst being the rear passenger bulb! Changed to full LED for interior, left all external bulbs apart from reverse lights alone. Number plate were originally LED. Car does look lovely at night when opening doors....As you get older you do appreciate the strongest clearest light you can find.