2021 Mazda MX-5 1.5L Petrol · S4 MDV

The multi-link rear suspension on the ND MX-5 uses spherical bearing pillow-ball bushings within the aluminium rear hub carriers (knuckles) to control wheel geometry. Over UK roads, moisture, road salt and grit penetrate the rubber dust seals, causing the internal spherical joints to corrode and develop excessive play. This produces a noticeable rear-end knocking noise over bumps, vague high-speed stability, and an automatic UK MOT failure for excessive play in a suspension pin, bush or joint. Mazda does not supply replacement bushes separately, quoting £900–£1,600 to replace complete hub assemblies; however, independent specialists fit aftermarket polyurethane or spherical replacement bush kits (such as Polybush or Powerflex) on the car.

On soft-top ND models, the folding roof frame geometry and tight clearances allow the canvas fabric to rub directly against the sharp edges of the plastic headrest roll hoop covers (seat-back bar garnishes) as the roof is lowered or raised. Repeated friction abrades the outer cloth fibres, creating visible whitening, scuffing and eventual through-holes in the fabric just behind the front edge. Mazda issued Technical Service Bulletin 09-023-19 to address roof contact, modifying link stoppers and clearances under warranty. On used cars out of warranty, fitting aftermarket clearance spacers, protective felt tape or replacing damaged hood sections is necessary.

The ND MX-5 utilizes rainwater collection basins with integrated one-way flap valves and removable debris filters located behind each seat belt tower. In the UK climate, pine needles, pollen, road grit and tree leaves easily bypass the grills and clog the narrow plastic drain tubes. When blocked, rainwater cannot drain under the car and overflows down into the cabin, accumulating under the rear parcel shelf insulation and soaking the front footwell carpets. Standing water can submerge the audio wiring loom and the sensitive Bose audio amplifier or control modules mounted under the seat, creating severe electrical corrosion and musty damp odors.