Changing the exterior lights (turn indicators, brakes, reverse lights, running lights) and NOT using the original bulb is basically illegal. The light pattern for those lights is based on the reflector design and assumes a filament based bulb to work correctly. Ditto for the amount of light being output.
Obviously modern vehicles that come equipped with LED indicators have light fixtures designed to use the LEDs (most often an array of LEDs). Older vehicles or ones that came with an incandescent bulb do not generally handle a LED 'bulb' well since the light pattern from a LED (even an array) is nothing like that from an incandescent filament.
Most folk don't realise that all these vendors selling exterior LED replacement 'bulbs' are essentially providing non DOT approved light solutions. It obviously is in the vendors best interest (so they can sell their solutions) to NOT inform you or hide the information away in a corner of their website.
Example:
http://www.superbrightleds.com/carbulb_notes.php
Read the bottom disclaimer, which I quote here:
"For aftermarket use. May not comply with SAE or U.S. DOT standards
Warranty void if used in applications other than standard automotive replacement bulbs
All product specifications are subject to change without notice"
Note the somewhat subtle "may not comply with SAE or U.S. DOT standards".... It can be pretty well guaranteed they don't comply.
Anyhow, in general most highway patrol/policemen will ignore it - just like they ignore most of the totally illegal HID retrofits. It's still illegal though... That's why I wrote what I did in the 2nd post. It is also why I never made and LED based exterior lights when I was selling dome modules etc for 80's and 100's - I did not want to get into the whole legality issue if/when an accident occurs and some over-active lawyer/vehicle-insurance-company decides to go through things with a fine comb.
Anyhow, just thought I'd at least make folk aware of SAE/DOT legality, do as you will...
cheers,
george.
