Streatham Road dust and the airbox that has to cope
The A216 Streatham Road links Mitcham with Streatham and runs past industrial land, and the Figges Marsh junction where it meets London Road is signal-controlled and queues at peak times. Add the Willow Lane estates, the lorry traffic they generate and the open dusty stretch of the A236 across the Common past the old windmill, and the air a Mitcham car draws in carries a steady load of grit, brake dust and soot.
That lands in two places. The air filter protects the engine, and when it starts to restrict, the engine simply works harder for the same output and economy drifts down without anything feeling wrong. The cabin filter protects you — it comes with the major service, or as an add-on to this one — and when it saturates you get a slow blower, a misted screen that takes forever to clear and a musty smell with the fan on. The air filter is part of the full service; the cabin filter comes with the major, or can be added to this one.
The annual service goes well beyond filters, though. All four wheels come off, pad and disc thickness is measured and recorded, the brake fluid is tested for moisture, the coolant is checked for strength and a fault code scan is run across the modules. Then there is the underbody inspection, which on cars that cross the Common and the Wandle bridges regularly is where corrosion on brake lines and exhaust mountings gets caught early.
Written quote before any extra work, nothing fitted without a phone call, and a 3-month workmanship guarantee on repairs. Most cars dropped off in the morning are ready the same afternoon. The run down is the A217 to the Cricket Green, Cranmer Road and then Carshalton Road over the railway by Mitcham Junction into Hackbridge, about eight minutes. Outside the peak the bridge by the station is clear and the run takes less.

