Is it possible to adjust the settings, such as turning off the DRL's and other adjustments without taking it to the dealer for them to do it? I noticed that it can be done easily with 2010+ models, but I'm wondering if there is a way to make the adjustments on the 2007-09 models.

 

Unfortunately no. Lexus started giving you that option with the 2010 model year.

 

Is there a device that can be purchased for a reasonable price to be able to make those adjustments ourselves?

 

Would love to find one. My dealer made the changes for no charge. But the convenience of doing it myself would be worth the price. I wonder if an OBDII Automotive Scan Tool and Virtual Dashboard could change them?

 

You will need this interface :
http://www.drewtech.com/products/Mon...ngoosemfc.html
with a subsription from this:
https://techinfo.toyota.com
and your laptop to do the job.
A shop that works on Toyota a lot should have those.