Skip advert
Advertisement

Rustbuster Full Hot Fog Treatment review

Rustbuster's Full Hot Fog Treatment is a thorough way to tackle early rust, but it comes with some messy side effects

Rustbuster Full Hot Fog Treatment - spraying underneath
Overall Auto Express rating

3.5

Even if the top parts of your car are kept shiny and the engine is serviced, the hidden corrosion underneath can consign it to the crusher before its time. 

One of the models which has developed a reputation for rust is Mazda’s MX-5, and our car was starting to look the wrong shade of red underneath. To ensure it survives, it was treated to a full proofing from Rustbuster. 

Rustbuster Full Hot Fog Treatment - rusty underside of a Mazda

This two-day process at the company’s HQ in Spalding, Lincolnshire, involves the car having its wheelarch liners and other covers removed before the underneath is steam cleaned and washed using degreaser and salt remover. It is then dried before the company’s Fe-123 Rust Converter is applied. 

Advertisement - Article continues below

The exposed areas and cavities are then coated in heated Corrolan, a lanolin-based product, which self-heals if hit or scraped. The company certainly does a thorough job. Our only complaint is that there was some waxy overspray, and the smell suggests some has found its way onto the exhaust too. The warm weather has also meant there is a steady trickle of melted wax from many parts of the car. It is easily removed with degreaser, but will stain driveway paving if left. 

The treatment is a big investment too. A small car like our Mazda MX-5 costs £654, while a large model such as a Volkswagen Passat is £774.

Did you know you can sell your car through Auto Express? We’ll help you get a great price and find a great deal on a new car, too.

Skip advert
Advertisement

New & used car deals

Volkswagen Tiguan

Volkswagen Tiguan

RRP £38,050Avg. savings £3,270 off RRP*Used from £24,991
Audi A3

Audi A3

RRP £26,310Avg. savings £2,531 off RRP*Used from £10,195
Vauxhall Corsa

Vauxhall Corsa

RRP £19,705Avg. savings £6,173 off RRP*Used from £8,938
Nissan Qashqai

Nissan Qashqai

RRP £27,435Avg. savings £5,987 off RRP*Used from £8,995
* Average savings are calculated daily based on the best dealer prices on Auto Express vs manufacturer RRP
Skip advert
Advertisement

Most Popular

New Dacia Striker 2026 preview: prices, specs and release date
Ellis Hyde with the Dacia Striker

New Dacia Striker 2026 preview: prices, specs and release date

The rugged yet athletic estate car is, in essence, an Audi A6 Allroad for a third of the price
News
10 Jul 2026
Car Deal of the Day: Big-battery Citroen e-C3 Aircross for a tiny £154 a month
Citroen C3 Aircross UK - full front

Car Deal of the Day: Big-battery Citroen e-C3 Aircross for a tiny £154 a month

The Citroen e-C3 Aircross offers space and a decent electric range for a low price. It’s our Deal of the Day for July 8
News
8 Jul 2026
New BYD Dolphin G arrives in the UK for a huge £6k less than key rivals
BYD Dolphin G Goodwood

New BYD Dolphin G arrives in the UK for a huge £6k less than key rivals

The BYD Dolphin G supermini gets big-car technology, with all versions costing less than £30,000
News
10 Jul 2026