JNC in Alfreton, don't know if they still exsist....
Noble Motorsport in Chesterfield.
Scooby Clinic also near Chesterfield.
Area52 or 51 (can't remember) Near J28, another Subaru specialists...
Used to be a company called Street Racers just near Leicester, but they moved to Loughborough and are now called something else, they have MaHa dynometers which always seemed quite accurate and upset most people.