Does the 350 not come with LED's from the factory?
I think the only factory LED lights are the "reading lights" (front and rear) and the courtesy lights in the footwells and near the center dome light (they create a faint blue/white glow at night. I think the ugly dome light that fades in and out when you open/close the door is an incandescent bulb. I think the door lights (on the driver and passenger doors) are also incandescent bulbs (the red ones near the corner of the door that come on when you open the door). I wanted to get the clear plastic covers (replace the red plastic covers) but I don't know if they are direct fit from the IS 300. Have you heard of any performance mods for the IS 350?
Not sure if LEDs will work properly in the dome light as they are dimmers. There are short ram intakes from LMS, FRAM and FUJI,.,., replacement induction duct from JOEZ, complete exhaust from LMS, or axle backs from TANABE, HKS(soon) and others, LMS is working on a supercharger, that's about it for now,...engine wise.