Modifying an exhaust to make it louder than when the car was manufactured is illegal in the UK but this can be flagrantly breached causing blight on people's lives and particular risk to horse riders.
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The law should be strengthened to ensure that MOT testing centres test the exhaust volume with appropriate equipment, based on the decibel limit of each individual car's exhaust when manufactured as provided by the DVSA.
There should also be higher penalties for testing centres who fail in this duty, and for drivers whose car exhausts have been modified to become louder.
Not only are illegal exhausts antisocial and blight the lives of many but terrorises horses long before the driver can be aware that a horse is affected. A bolting horse not only puts the life of the rider and horse at risk but also any other road user that it may crash into.