Wilcox Limousines are a market-leading specialist in modifying high-end production vehicles into limousines and funeral cars. Their vehicles have been distributed as all over the world and Wilcox have ambitious expansion plans for the future.

CAL International are market-leading specialists in OEM design modification and so naturally Wilcox came to CAL to extend their current range of vehicles to include the Mercedes E-Class stretch limousine and the high-end Bentley Flying Spur hearse. CAL design engineers and project managers worked closely with the Wilcox team to modify multiple aspects of the OEM design to deliver a full stretch variant whilst maintaining the original safety and aesthetic principles. In the case of the Mercedes E-Class, both Petrol and PHEV variants were designed and produced.

Bentley Flying Spur

Mercedes E-Class Petrol


 The core requirement for CAL design engineers is always to ensure that critical OEM features and aesthetics are carried over from the OEM into the new platform design. The critical challenge is to ensure that the finished modified vehicle preserves the quality, structural integrity and luxury aesthetic of the original OEM design whilst also meeting the new ‘stretch’ requirements.


 Step 1: Understand the customer’s needs

 The change to the OEM vehicles needs to be holistic and so the CAL design team worked with the Wilcox team to precisely understand the modifications they wanted and why. Asking ‘why’ is in the DNA of every CAL design engineer as sometimes it allows us to explore and evaluate multiple design options. The CAL team visited Wilcox HQ in Wigan on several occasions to ensure that all the wider implications of the proposed Design Requirements had been fully understood and costed.

Step 2: CAD design & design optimisation with FEA

 Once the Design Requirements had been agreed, and initial design potentials scoped out, the CAL team started the concept design phase that led to an iterative phase of further design optimisation in liaison with the Wilcox team. At each stage, the CAL team ensured that every design option met the wider OEM requirements to ensure there was no loss in function, strength, or durability

Throughout this project, due to the lockdown, much of the communication between CAL and Wilcox was done remotely by using detailed CAD models to demonstrate progress and discuss options and implications. One final design consideration was, ironically, to ‘work in’ as many pre-existing components to improve production efficiency and manufacturability of components across each vehicle.

FEA was central to the project throughout, allowing CAL to prove design options and rationalise components and material wherever possible.

The Wilcox Bentley is meticulously designed and engineered around the Flying Spur

STEP 3: Prototype and manufacture

 Weekly design reviews were conducted for the duration of the project and each live design aspect was marked as completed. Project gateways were reached as the project evolved from a concept into a full vehicle build where each area was validated for use on future builds.

If you would like to learn more about this project or discuss how we can help with your product or OEM modification project, please get in touch.

Established in 1948, Wilcox Limousines is the leading British family coachbuilder. It has the largest selection of new and used Funeral Vehicles in Europe and is the market leader providing Hearses, Limousines, Private Ambulances, Removal Vans and Hearsettes® based on Jaguar, Vauxhall, Volvo and Ford vehicles.

For more information about Wilcox Limousines, please visit: https://limousines.co.uk/