Any suggestions on how to rid a car-specifically the passenger leather seat- of smoke smell. My car was involved in a fire, my entire passenger side was torched and the interior of the passenger door melted. The body has been fixed, but there is still a strong smoke smell. I have had it detailed and new floor mats, etc. but I think the problem lies with the leather passenger seat.

There are vendors that specialize in odor remission for concerns such as yours. Searching the internet or contacting local car dealers may be your best bet.
Unfortunately, so many items in your car's interior may have been permiated with the smoke that nothing short of replacement will totally resolve the problem. They should tell you this before attempting any cleaning.
Your insurance company should be contacted, particularly if they were involved from the beginning.