I found that the size of the lug nuts for our 3IS is M12 x 1.5 Mag seat.
I found some on amazon (2 on the left of the pictures), but not sure which one will fit since their item dimension are different.
The one on the left item number is 00276-00900
The one on the second left is 00276-00901
Which one you recommend?

 

Pretty sure the one I have is 0900.

The 901 says it's for the GX470.

So pretty sure the first ones.

https://www.lexuspartsnow.com/parts/...276-00900.html
https://www.lexuspartsnow.com/parts/...276-00901.html

the second one may fit if it's the same thread dimension, but it would stick out way past cause it's made for a meatier SUV wheel.