Toyota Raize: Lower Door Sill and B-Pillar Base Corrosion

The Raize uses thin-gauge steel with minimal underbody coating on the lower door sill pressing and the base of the B-pillar — areas that trap moisture and road grime behind the plastic sill trims. In NZ and southern Australian climates with road salt exposure, surface rust develops within 2-4 years and can progress to structural perforation within 5-6 years if untreated. The failure is accelerated by stone chips on the lower sill edge that breach the factory paint, and by the design of the plastic sill trim which channels water into the cavity rather than away from it. This pattern is documented across multiple Japanese domestic market Raize and Daihatsu Rocky examples inspected at the 3-5 year mark.

• Rust bubbling or paint lifting visible along the lower door sill edge, often starting at the rear corner
• Brown staining or weeping rust around the B-pillar base when the plastic trim is removed
• Perforation or softness in the sill pressing when probed, particularly on vehicles over 4 years old
• Plastic sill trim retaining clips pulling out of rotted steel rather than plastic clips failing

1. 1

   Remove or flex back the plastic sill cover on both sides and inspect the pressed steel underneath for rust bubbling, perforation, or flaking paint.

2. 2

   Run a finger along the lower B-pillar weld seam at floor level.

3. 3

   Probe any bubbled paint with a blunt tool — soft spots indicate active sub-surface corrosion.

4. 4

   Also inspect the front floor pan edge where it meets the sill from underneath the vehicle.

5. 5

   In vehicles imported from Japan, ask for the full import history and check for evidence of prior rust treatment or underseal reapplication.

Parts involved: Body corrosion.

$600 to $2,800 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

• “Has the vehicle ever had rust treatment, underseal, or sill repairs carried out?”
• “Can I remove the plastic sill trim to inspect the steel underneath before purchase?”
• “Has the car spent time in a coastal or high-rainfall environment where road salt is used?”

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.