Has anyone added these options after purchase, is it possible?

 

Not possible. Dealers don't want to take responsibility for safety items like these. Parts and labor also would be pretty pricey too; to the point where it would probably make sense to trade your car in for a car with the features installed at the factory.

 

Yes you can, but spend a lot of time and money. I found some accessories on Taobao website. They are not aftermarket accessories, they are original accessories made by Lexus. Buy and fit by yourself. It will not easy

 

Can you post a link? I'm really interested in radar cruise control...