Technical Regulations for Street Categories

The exhaust system must exit at the rear of the vehicle.
Aftermarket air filters, intercoolers and intercooler piping are permitted.
Aftermarket throttle bodies are permitted.
Aftermarket oil coolers are permitted.
Aftermarket radiators are permitted, provided that they remain in the original OEM location.
Aftermarket clutches and/or flywheels are permitted.
The transmission must remain OEM. Components from other models produced by the same manufacturer may be used.
The original battery may be replaced with a lightweight battery. The positive terminal must be properly covered and insulated.
If the battery is relocated to an area connected to the passenger compartment, it must be securely installed inside a sealed battery box.
ECU tuning and software upgrades are permitted.
The air-conditioning system, heating system, audio system, airbags and all associated components may be removed, provided that the vehicle remains above the minimum weight specified for its category.

The chassis must not be modified or structurally altered in any way.
The vehicle’s wheelbase must remain unchanged.
OEM or aftermarket control arms may be modified or used for suspension and camber adjustment.
Aftermarket coilovers and adjustable shock absorbers/dampers are permitted, provided that the vehicle’s track width remains unchanged.
Aftermarket anti-roll bars are permitted.

The convertible roof operating mechanism may be removed and replaced with an aftermarket roof.
Carbon-fibre or fibreglass components may be used for convertible roofs, bonnets, bumpers, front and rear wings, and overfenders, provided that the vehicle remains within the permitted minimum weight for its category.
All structural chassis panels must remain original and unmodified.
Replacement of the original windows with alternative materials—including Lexan, Plexiglas or carbon fibre—is prohibited. The only exception is the rear window of roadster vehicles.
All other OEM windows must be retained and remain fully operational.
Aftermarket splitters are permitted.
Splitters must not extend more than 15 cm beyond the vehicle body at any point around its perimeter.
Rear diffusers are permitted.
Aftermarket rear wings and spoilers are permitted.
On vehicles other than hatchbacks, the rear wing must not extend above the highest point of the vehicle or beyond the overall width of the wheel arches.
On hatchback vehicles, the rear wing may extend up to 15 cm above the highest point of the vehicle.

A complete interior, in accordance with the vehicle manufacturer’s original specification, is mandatory.
The interior may be modified for safety purposes. Permitted modifications include two front bucket seats of a recognised safety standard, an aftermarket steering wheel, safety harnesses, roll bars and safety cages.
All safety seats and associated equipment are subject to inspection and approval by the Scrutineer.
Safety cages must be of a bolt-in design only. Welded-in safety cages are prohibited.
All interior panels, headlining, carpeting, dashboard, upholstery, plastic trim and A-, B- and C-pillar trims must remain OEM. The rear luggage compartment is exempt from this requirement.
All vehicles must retain operational OEM front and rear lights and an operational horn.
A limited-slip differential (LSD) is permitted.
The final-drive ratio may be changed.
Brake-system modifications are permitted.
There is no restriction on wheel diameter or width, provided that the tyres fitted comply with the applicable category regulations.
Brake-cooling ducts are permitted.
All vehicles must be equipped with a securely mounted fire extinguisher of at least 2 kg, positioned within easy reach of the driver.
At least one towing eye or tow hook must be fitted at the front and one at the rear of the vehicle.

Any component, system or modification not specifically mentioned in these regulations must remain OEM. Its replacement or modification is prohibited.
Vehicles that do not fully comply with the requirements set out in these regulations will be examined and assessed individually by the Technical Committee.