BinaryJava

Hi all, My brother in law is looking for a cheap unmodified Impreza WRX (06-08) as his second car and we have a couple of questions about the general cost of maintenance and repair. Does anyone have a recommendation for any garages in Essex that specialise in Impreza rebuild and repair What parts are recommended to be replaced at what mileage? How many miles between oil changes? What should we be looking for when we go to visit the car, coloured exhaust smoke? Thanks