Er! You asked about LED lamps or bulb replacements and if you are in the UK or
Euro land then if NOT type approved then illegal and cannot be fitted for road
use.  However as it appears that anything goes in the USA then fit and be dammed
and stop moaning.

If you don't like the answers don't ask the question.

Which doesn't answer my question.
I wasn't after a legal lecture - there's other more appropriate groups
for that

Which means that they are illegal to use on the road.

You're probably right but these ones have high intensity pointing to the
rear with side clusters for the reflectors
They *may* be very good and I think I will give it a go with front
indicators first
As for E marking - the lack of it doesn't mean they don't comply, it
merely means they haven't been type approved. This could be due to tyhe
fact that it costs  so much to achieve these markings. It's rather like
saying that someone who has passed a driving test is a better driver
than someone who hasn't - which of course is not necessarily true (just
that passing proves it!).
Worth a try for £5

These simply don't produce the same light levels as a 21 watt indicator
bulb in the normal reflector.

Euro car lighting parts must be 'E' marked to conform with those regs. And
non of these replacements are - simply because they can't produce the
correct spread of light at an intensity to replace a 21 watt filament
type. The other type of LED replacement with 5mm leds 'firing' forward do
just about produce the same intensity - but only over a very narrow angle.

For safety lights like indicators etc where a wide viewing angle is
required these things are positively dangerous - they can't be seen in
bright daylight.

Take a look and tell me what you think - these seem pretty well designed
to widen the viewing angle:
http://www.virtualvillage.co.uk/Items/002510-030?

For a start there are no direct replacement LEDs for units designed for
tungsten - the optics on these lights is optimised for a point source
filament. And for things like indictors this is a very real problem in
sunlight etc - the LED replacements simply won't be as bright, or have the
same viewing angle. And it's not just a slight difference either. There
are currently no LED replacements that meet the specifications required by
law in Europe. Completely new lamp units designed from the start for LEDs
are a different matter.

They will also confuse the failed bulb warning system.

Can anyone advise me if fitting after market LED bulbs in indicators,
side adn brake lights confuse the onboard computer?
I prefer the more responsive light they offer but don't want the car
dinging me about dead bulbs!

I've a 2001 E39

Thanks
David