Craig, looks like you have an awesome opportunity in front of you. I hope you'll read this post before going further with the LED conversion.
I communicated with Marek H by email seeking direction to his previous posts on this topic. He very kindly replied and included detailed technical advice on why it's a BAD idea to use an LED for the ignition light. I will attach his comments below.
A word of caution - before purchasing my LED kit, I spoke with a tech person at the vendor's and asked specifically about this; he assured me it would be okay. Marek has convinced me it's NOT, and I will be reverting to a filament bulb (incandescent for those of us on this side of the pond) for this application only, retaining LED's elsewhere in the interior. If anyone would like NINE 987 LED's drop me a private nessage
Here are Marek's words of wisdom: "To produce any charging voltage, the alternator needs current to excite the field coil and this comes through the warning light so a directional LED isn't appropriate in this application. The light is also only on for a few seconds at startup, so there is no point upgrading it. The longevity of a filament bulb in this application appears to be in excess of 50 years as it is only used for a few seconds per trip.
The green turn signal jewels can use LEDs on the s3. The advice given to you here to not use them pertains to s1 cars. Once again though, there is no real benefit, as the turn indicator bulbs are almost never on, so no amount of tinkering will result in any real upgrade. The flasher and hazard cans work via a bimetallic strip which depends on drawing sufficient current to get them to make and break the circuit to cause the flashing, so switching to LEDs for the four turn indicators entails also changing the flasher can and hazard cans as LEDs all round don't draw enough current to make the circuit flash. The most sensible upgrade here is to simply swap out either the front OR the rear bulbs for LED bulbs if and when one of the filament bulbs has failed. That way, you don't waste money and still running one filament bulb per side means new flasher cans aren't needed.
There is no practical advantage in using LEDs for the fuel warning light or the high beam either. Use some common sense. These bulbs are almost never on or at least run form the alternator, not the battery, so there is little or no benefit in swapping them out.
My experience is that you need more illumination for the two large dials than you do for the smaller centre gauges."
Good luck, all, and thanks again, Marek
