Ok i have been doing a little research on the SWI-X but i still dont really get it.
1. Hold or tape the Infrared LED (blue LED on black wire) to a surface so it is facing towards the aftermarket stereo. It must have a clear line of sight to the stereo. Try to minimize the angle as much as possible.
The best place to mount the LED: In the center console or overhead console (extending the LED wire may be required) and as far back as possible. Behind the domelight cover.
Bad places to mount the infrared LED: Do not mount the LED in stereo installation kit. Do not place LED where cups or other articles will block it. If at all possible, try not to mount where sunlight may shine on LED.
How big is this LED? Where should I mount it on a 2009 mazda 3 Sedan? This is just confusing. I just wanna wire some stuff up behing the stereo and be done with it lol.