The thing is, it might not be a simple swap out, one way to find out was to take it apart...did you?

 

Switching to LEDs for vehicles which are not ready for them could also cause other issues, for example on my GM SUV, a resistor is required as the LEDs could interferre with the cruise control (funny as it may sound).

 

I know some one that put LED'S on his car from http://www.superbrightleds.com/led_prods.htm I do not know how they would function on the Lexus at all. I have purchased outdoor LED'S from them with good results. However they have a warning page about possible car issues using LED'S.