There are cars we'd only agree to sit in as long as we're wearing a clothespin on our nose. No one will want to rent, much less buy and own such a car.
We have the solution:
Go ahead and spray Skyvell Spray on everything: Headliner, car upholstery, carpets/mats, trunk and ventilation/air blower unit (if the smell is extreme, spray multiple times over the bonnet into the absorption device of the interior blower). All bad odours are being instantly and permanently eliminated on a molecular level, which results in a pleasant, subtle scent. The car is now available again and can be sold or rented.
The fact that nothing is completely clean until the bad smell is gone, goes for every environment. Skyvell makes a vital contribution by effectively eliminating all kinds of malodours.