Toyota Sienta: NCP80 Sill and Rear Wheel Arch Rust (JDM Import)

The NCP80/NCP81 Sienta body was built for Japanese domestic market conditions and uses limited rustproofing compared to export-specification Toyota vehicles sold in markets with road salt. NZ grey imports are now 12–20 years old. Rust initiates at the base of the B-pillar where the sill meets the floor, at the rear wheel arch lip, and at the lower rear door aperture seal channel. The sliding rear door track lower bracket is also prone to rust-through. While surface rust is cosmetic, sill rail perforation affects structural integrity and can lead to WOF refusal on structural corrosion grounds.

• Bubbling or blistering paint along the lower sill seam
• Visible rust at rear wheel arch lip or lower door frame
• Water ingress or damp carpet inside near B-pillar
• Sliding door lower track feeling sticky or corroded
• Perforation visible from underneath at sill edge

Run your hand along the full length of the lower sill from front to rear — bubbling paint under your fingers indicates rust from within. Squat and look at the rear wheel arch lip for rust. Inspect the sliding door lower track and bracket from inside and outside. Use a flashlight under each B-pillar to check for sill perforation. Probe any soft paint areas with a key to test for hollow rust pockets. If a workshop inspection is possible: Lift the rear floor carpet and check for moisture or rust on the floor pan near the rear sill.

Parts involved: Body corrosion.

$300 to $3,500 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 car had any rust treatment or underbody protection applied in NZ?”
• “Has any rust been repaired on the sills or wheel arches?”
• “Has the car ever had wet carpet or water ingress inside?”
• “What part of NZ has the car been in — coastal area?”

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.