The restomod has become a significant part of the high-end classic car market. A “restomod” is a classic car that has been restored and substantially modified. It retains the identity and appearance of the original but may gain a modern engine, brakes, suspension, electronics and interior.

The recent UKIPO decision in Mercedes-Benz Group AG v Thornley Kelham Ltd provides a timely reason to consider how the brands attached to these cars should be used. Thornley Kelham sought to register a logo containing EUROPEAN SL for cars and car design services. Mercedes-Benz opposed, relying on its earlier rights in the SL model designation. 

Mercedes-Benz prevented registration for cars, but not for car design services. The decision was not about whether restomods are lawful. It nevertheless exposes a wider issue: when a specialist transforms a recognised classic car, how far may it use the identity and reputation of the original manufacturer?[1] 

Specialists including Singer Vehicle Design, Gunther Werks, Eagle E-Types and Thornley Kelham combine recognised classics with modern engineering. Their work can be worth far more than the original or “donor” vehicle. Much of that value depends on the original car’s identity and reputation. 

Identifying the donor or branding a new product? 

There is nothing inherently objectionable about saying that a business restores or modifies Porsche 911s, Jaguar E-Types or Mercedes-Benz SLs. The original brand and model may be necessary to explain what the business does and what the customer owns. 

The risk increases when the brand or model name performs a different function. Rather than identifying the donor, it begins to brand the finished product. Compare: 

“A customer’s Porsche 911 restored and modified by X” 

with: 

“The new X Porsche 911 RS” 

The first describes the vehicle’s history and who carried out the work. The second may suggest a new model, collaboration or manufacturer approval. Most examples fall somewhere between them. 

Thornley Kelham presents named projects including the Porsche 911 European RS and Porsche 356 European SL.[2][3] That is not to say the presentation is unlawful. It illustrates the spectrum between description and a repeatable, model-like commercial proposition. 

The badge carries responsibility 

The most interesting issue may not be confusion at the point of purchase. A customer commissioning an expensive restomod is unlikely to believe that Porsche, Jaguar or Mercedes-Benz is carrying out the work. A later buyer, journalist or member of the public may know much less. 

The wider public sees something different. It sees the badge. 

The badge carries expectations about engineering, reliability, safety and quality control. It may communicate responsibility as well as origin. 

A restomod may retain its original chassis and registration identity but have a new engine, suspension, brakes, electrical architecture and bodywork. Its behaviour may be determined more by the restomodder than the original manufacturer. If it is involved in a serious accident, it may still be reported simply as a Porsche or Jaguar. The manufacturer may have no legal responsibility, but reputational damage can occur before the cause is known. 

Could a poor restomod damage the original brand? 

The UKIPO decision does not answer that question. In an infringement dispute, however, section 10(3) of the Trade Marks Act 1994 provides an interesting lens.[4] It protects trade marks with a reputation against uses that unfairly exploit or damage that reputation. It does not always require evidence that customers were confused about who produced the goods. 

An automotive brand might argue that its mark remains prominently attached to a vehicle whose performance and safety have been materially altered by another business. If that vehicle is badly engineered or involved in a high-profile accident, the public may still associate the consequences with the original manufacturer. 

Liability would not be automatic. A court would consider how the mark was used, whether the public connected it with the manufacturer, whether there was proper reason for the use and whether harm was sufficiently likely. The concern is that a mark continues to give assurances about characteristics the manufacturer no longer controls. 

Singer and the dual-attribution model 

Singer Vehicle Design offers a useful example of how the interests might be balanced. Singer carries out extensive restoration and re-engineering of Porsche 911s, principally using 964 model cars. The results are presented as the “Porsche 911 Reimagined by Singer”. Singer also states that it is not sponsored, associated, approved, endorsed or affiliated with Porsche.[5] 

The wording performs three tasks:

• Porsche 911 identifies the original vehicle and its heritage. 
• Reimagined by Singer identifies who undertook the transformation. 
• The non-affiliation statement addresses the absence of Porsche approval. 

This is useful dual attribution. Porsche identifies the vehicle’s origin. Singer identifies responsibility for its re-engineering. 

The balance matters. The builder’s name must be prominent enough to identify responsibility, not a small qualification to much stronger manufacturer branding. A disclaimer hidden in website terms cannot necessarily correct badging or marketing that suggests factory involvement. 

Clear attribution, on the car and beyond 

Removing every original badge would deny an authentic car’s history. Leaving only that badge may misallocate responsibility. Clear dual attribution offers a more balanced answer. The original brand can identify the donor, its origin and history. The restomodder can identify who designed, engineered and carried out the transformation. 

That message should appear in advertising and on the car itself, its build plate, engine bay, documentation and service records. A restomod may outlive its original marketing and pass through many owners. Attribution needs to travel with the car. 

The message might be: 

Built from an original Porsche vehicle. Independently re-engineered and rebuilt by X. Not approved or endorsed by Porsche. 

This will not resolve every trade mark, design or liability question, and a disclaimer will not cure misleading presentation. But it recognises both the restomodder’s reliance on automotive history and the manufacturer’s interest in showing where its responsibility ends.

Sources

[1] UK Intellectual Property Office, O/0787/26, SL & European SL (Figurative), decision dated 27 August 2026. UKIPO decision (PDF) 

[2] Thornley Kelham, “Porsche 911 European RS”. Thornley Kelham - Porsche 911 European RS 

[3] Thornley Kelham, “Porsche 356 European SL”. Thornley Kelham - Porsche 356 European SL 

[4] Trade Marks Act 1994, section 10. legislation.gov.uk - section 10 

[5] Singer Vehicle Design, Automotive and trade mark notice. Singer Vehicle Design - Automotive