Start by finding the source rather than just masking the odour. Check under floor mats, in the boot, and around door seals for damp patches, hidden spills, or trapped debris. If you can’t locate the source, the smell will return no matter what product you use. Once you’ve found and cleaned the contaminated area, use an enzyme-based odour neutraliser to break down any remaining smell molecules in the fabric or carpet. Give it time to work, usually several hours or overnight, then ventilate the cabin thoroughly. Air fresheners might be tempting, but they just cover the problem temporarily rather than eliminating it.

Enzyme-based neutralisers work best for organic odours like food, pet accidents, or mildew. They break down the compounds causing the smell rather than just masking them with fragrance. For general mustiness or stale air, activated charcoal or odour-absorbing gels placed in the cabin pull smells out of the air over time without adding artificial scent. The most effective solution depends on what’s causing the odour. Strong smells from specific sources need direct treatment with a neutraliser, while light staleness responds well to passive absorbers. Avoid relying on air fresheners alone, they might smell pleasant initially, but the underlying odour always returns once the fragrance fades.

Cigarette smoke is one of the hardest smells to remove because it penetrates fabrics, plastics, headlining, and ventilation systems. It won’t go away on its own, you’ll need to deep clean all interior surfaces, treat fabrics with a strong odour neutraliser, and clean or replace the cabin air filter. Even with thorough treatment, some residual smell often lingers because smoke particles settle into areas that are difficult to access and clean properly. Multiple treatments combined with extended ventilation give the best chance of success, but expectations need to be realistic. It’s a process that takes time and persistence rather than a quick fix.

Dealerships often use ozone generators to neutralise odours at a molecular level. The ozone reacts with odour-causing compounds and breaks them down, which is effective for stubborn smells that cleaning alone doesn’t shift. However, ozone treatment requires the car to be unoccupied for several hours and needs proper ventilation afterwards. For routine deodorising, they use enzyme-based neutralisers on fabrics and carpets, followed by a light application of air freshener to leave a fresh scent. The key difference is that they address contamination first through cleaning, then use deodorising products rather than relying on fragrance to cover up the smell.

For odour absorption, leaving baking soda sprinkled on carpets and seats overnight or for 12 to 24 hours gives it enough time to pull moisture and smells from the fabric. Longer doesn’t necessarily work better, once it’s absorbed what it can, additional time won’t make much difference. The bigger issue is thorough removal. Baking soda needs to be vacuumed out completely, and it can leave a white residue in carpet pile if you don’t extract it properly. From our experience, it’s useful for light odour control between proper cleans, but it’s not a substitute for actually cleaning contaminated areas and treating them with a proper neutraliser.

Enzyme-based neutralisers designed for severe organic contamination are generally the most effective for stubborn smells. They break down proteins and organic compounds at a molecular level, which eliminates the odour rather than just covering it. Products formulated for pet urine or decomposition tend to be the strongest, as they're designed to handle the worst-case scenarios. Ozone generators are also very powerful but require professional use and proper ventilation. They're not something most people can or should use at home, as ozone can damage materials and is harmful if inhaled. For DIY odour removal, a strong enzyme neutraliser combined with thorough cleaning and drying is your best approach.

The "new car smell" dealerships create isn't actually natural, it's a combination of thorough cleaning, deodorising, and often a specifically formulated air freshener designed to mimic that scent. The real work happens in the deep clean that removes any existing odours first. They vacuum and clean all surfaces, treat fabrics with odour neutralisers if needed, replace the cabin air filter, and make sure the interior is completely dry before applying any scent. The fresh smell only works because there's no underlying odour competing with it. Trying to achieve that smell without addressing contamination first just results in mixed odours that smell worse than either on its own.