I purchased a used (smokers) car that the dealer had heavily concealed with air fresheners etc to mask the smell. After a few days the cigarette smell came roaring back and was quite unpleasant. I did a fair bit of research and came across Biocide Systems range. Being in Australia, the product was a little more expensive due to shipping , but it was worth every dollar. Applied exactly like the instructions said and the smell was gone in 24 hours and has never returned. Highly recommended. Thanks again Sean Perth Australia