Those who buy a used car may be driving legally without ever having made any changes. This happens when the previous owner modified rims, tyres, windows, engine or other components without completing the legally required procedures. Article 114 of the Road Code prohibits the circulation of vehicles with non-approved systems, components or accessories, and Article 115 considers any alteration of the constructive or functional characteristics of the vehicle as a transformation.
The Institute of Mobility and Transport warns that, for example, different rims from the originals may not constitute an irregularity, but it is important to confirm whether the mounted dimensions are authorized for the vehicle. Tinted films applied afterwards also constitute a transformation and require endorsement on the registration certificate, after approval in an extraordinary inspection at a category B inspection centre. IMT also considers the alteration of the structure, bodywork, engine, systems or components of a registered vehicle as a transformation, requiring prior authorization when the alteration may compromise road safety.
Fines for driving with non-approved systems can reach up to 1,250 euros, with vehicle seizure until approval in an extraordinary inspection. Transformation without authorization is subject to the same fine, unless a more serious sanction applies. Article 135 of the Road Code establishes that violations relating to the conditions for admission of the vehicle to circulation generally fall on the holder of the identification document, although the application of a fine depends on the assessment of the specific case.
The relevant question when buying a modified used car is not whether it was the current owner who altered the vehicle, but rather whether that alteration is effectively approved and regularized according to Portuguese law.
