I have throught some investigation and effort worked out the correct way to disable Daytime Running Lights on the RX330 and 350. This is reversible, and does not affect High Beams or any other function. It is a simple 30 minute process.
Daytime running lights are optional on many cars, and can be software disabled on many Lexus models. I do not know why Lexus chose to omit the option of turning them off in the RX330.
There is NO legal requirement for DRL in any US state. Further, there is NO sanction for disabling them in any US state. Canada may well be different.
The studies of DRL effectiveness came out of Canada when few cars used DRL. It is an unanswered question whether DRL is effective in reducing accidents when many or most cars have them. It is also unanswered whether DRL is as effective at latitudes with much ambient daylight, such as the southern US.
So, If you want them, keep them on and use them. Realize that in rain, drizzle, snow, fog, dusk, or overcast, DRL has NO taillights. In those conditions, full headlights and taillights are the safe alternative.
If you do not want DRL for aesthetic or other reasons, there is a safe, easy, reversible option. If anyone is interested, please let me know and I will post instructions in a new thread.