This Cree LEDs have a lot of emitters with not a lot capacity to dissipate heat. I would only use those for short duty cycle installations. If you run those for any sort of extended period of time (DRLs, for example), they will fail prematurely and/or lose a significant portion of their output. They are also not suitable for high beam installation, as the light output won't have any sort of focus to it.
As for the Lexus LS600h, I'm pretty sure its high beams are LED, but in a separate projector from the LED multi-lens projectors.
You could use separate HIDs for high beams, but you will need a rapid start ballast that provides a surge during startup to bring the lamp up to temperature (and full output) much more quickly than standard ballasts.