This classification usually accounts for between a quarter and a third of all event entries at Harewood.  These cars are often based on very familiar road cars that many of us see each day on our roads.  Typically these cars will be hot hatches or high performance saloon cars.  Modifications and road tyre types are tightly controlled and things like interior trim cannot be removed, although safety features such as roll over bars can be added.

Many cars in this group are based on Colin Chapman’s famous Lotus 7, such as Caterhams and Westfields.  They are usually two seater sports cars from low volume producers, which are relatively light in weight and use engines and gearboxes from mainstream manufacturers such as Ford, Vauxhall and Rover.  Modifications and tyre types are tightly controlled.  These cars can be very competitive and can be run on a realistic budget.

This classification covers the same type of cars as the Road Modified and the Kit Car groups, but allows more extensive modifications to the engine, suspension and bodywork.  The two ‘Mod Prod’ groups cater for saloon/sportscars (classes 6 to 8) and kit cars (classes A to C).  Interior trim can be removed and some glass replaced by Perspex.  Engine and gearbox types used must have been supplied in these cars by the vehicle manufacturer.  These cars can run on racing tyres with no tread (slicks).

This is special class for pre-1994 Formula Ford race cars, which use the Ford ‘Kent’ engine.  The cars have no aerodynamic aids such as wings and engines are tightly controlled as are tyres that can be used.  As a result competition can be very close and limits the budget required to buy and run these cars.

These are special hillclimb racing cars and can be distinguished by their cycle type mudguards.  There are restrictions on the engines and gearbox used e.g. the gearbox cannot be sequential and the number of ratios is limited to four for a front engine and five for a rear engine car.  Slick tyres will normally be used.

This is a classification which caters for sports racing cars, special saloons, GT1 sports cars, World Rally Cars and cars that don’t qualify for other groups.  All cars in this category have full width bodywork, aerodynamic devices and generally run on slick tyres.  Engines can be car or motorbike derived and gearboxes can be sequential.  Libre in French means ‘free’ and so the modifications allowed here are fairly flexible. 

This category is for single seat open wheel racing cars, invariably running on slick tyres.  The cars will have sophisticated aerodynamic wings and generally be of a very low weight.  Often the smaller capacity engine cars are powered by motorbike engines (light weight and high revving) with sequential gearboxes.  The larger engine capacity cars can be powered by ex-F1 engines of 3.5 litres or more and resemble an F1 car in looks.  The body and wings are often made of carbon fibre for strength and to reduce weight.

Various classes are created for ‘invited’ clubs e.g. Aston Martin, Austin Healey, Austin Seven, Bentley, Ferrari, Ginetta, MG, Morgan, Porsche, TVR, motor bikes etc.  This allows cars and bikes of a like marque, club or championship to compete against each other.  Not all classes attend each meeting.