.....-Replace interior light....
As for the interior lights....(front) I can't see why people want to change it as the
amount of light it 'chucks' out (it is a halogen bulb, not like a normal bulb) is more
than adequate and the novel functionality (twist n turn for different light patterns)
would be lost if anything else was somehow managed to fit into it.
LED's now are so common place and to be honest, how often do you ever have the
need for that much of an intense light ? It might be wise just to pull the unit
out and give it a good clean as they normally are quite bright, though I've seen
a few that were a bit discoloured/dirty.
(and the rear)...careful..as the unit has a dual acting /'rocking' function that
switches the power, so a normal LED wont work on one setting...and I've yet
to find a 'bi-polar' (works whichever way the power is) festoon LED of the
same size that will fit straight in.
But apart from that...yes I do know and have seen 3 ForFours that have had
there fusebox 'fried' when their owner changed the interior bulbs to LED's
without first disconnecting the battery !
Why the battery, well it's far 'safer' than doing it with the doors closed as
it is so easy/simple to forget why you have it closed and just open it for
possibly more room or the freedom to move about for whatever reason.
Having LED's is a personal choice...