If you have access to one from a friend or if you feel compelled to purchase one yourself I'd do at least two passes with an O3 unit. Preferably this is done with at least the front seats out and with the aircon system set at max fan speed and recycle (with the cabin filter removed - consult your lexus manual about how to safely remove that).

Something like this which I invested in after purchasing a car from a smoker:


Just be careful because O3 doesn't mix well with humans.

 

I was also going to suggest O3 saturation, it works wonders to purify a car before selling it. You can take a car with 1-3 inches of cigar ash in the cup holder and imbedded into everything to totally clean but the smell never leaves until you hit it with O3

 

I considered ozone treatment but ultimately decided against it (purely budgetary, grad student stipend is incredibly oppressive). So far happy with the results, but I'd likely rent/purchase one if I did this all over again, considering an additional ~$100 is well worth the peace of mind in the long run.

I also purchased my LS from a smoker. I got rid of the smell by thoroughly detailing the interior then emptying an entire ozium spray into the cabin and through the intake area. O3 sounds like it would've been easier though.

 

That machine covers 2000 sq ft. Way more than a car's interior. Very impressive for the cost. There's also a $55 machine that should be fine as well. Either machine, start with some physical cleaning of the interior including underside of seats. Once you know the "secret" it's very doable.