A 3rd owner car with 18k miles on it? I will honestly never understand my fellow Crossfire drivers....lol. I bought my SRT-6 with 42k on it (thinking THAT was low mileage) back in March '14 and it's up to 57k now with it being my 2nd car + working from home full time! Anywho, this is irrelivant to the topic at hand.

Like most, my Crossfire has the beloved "melted crayon" smell too. To be honest, it doesn't particularly bother me that much. I have pretty much to terms with the fact that this is just how Crossfire's smell. I have tried a few of the solutions you mentioned above, however I can confidently state that all of those solutions will be temporary. The car bombs I have done mask the scent for maybe 24 to 48 hours tops. I usually use Febreze Auto spray on my carpets, seats & rear hatch area every time I wash my car. It's not that I mind the melted crayon smell, I just prefer a "fresher" smell if possible. Again, the Febreze doesn't rid the car of the smell, but it does well in hiding the smell for a small period of time.