The 1986–1993 Toyota Supra (A70) is now 30+ years old, and rust is the biggest threat to surviving examples. This guide identifies every common rust area on the MK3 Supra, explains how WestNet One Stop Shop Paint Enamel’s 3-in-1 formula provides lasting rust protection, and walks you through a complete treatment process.
These are the areas where A70 Supras develop corrosion first. Knowing where to look allows you to catch rust early before it becomes structural.
The rear wheel arches are the most common rust area on any MK3 Supra. Road spray, salt, and debris collect behind the plastic wheel well liners. Rust starts from the inside and bubbles through the outer paint. Inspect by removing the liner and checking the inner sheet metal.
The bottom edges of the rocker panels trap water and road grime inside a boxed section. Drain holes can clog, causing moisture to sit against bare metal for weeks. Rust progresses invisibly until the outer skin perforates. Tap the lower sills with a fingernail to check for soft spots.
The recessed channel around the rear hatch opening collects water when the rubber seal ages and cracks. Rust forms along the bottom edge of the hatch opening and can spread into the rear quarter panels. Replace the seal and treat early.
Acid fumes and occasional electrolyte spills corrode the battery tray and surrounding sheet metal in the engine bay. The tray is easily replaced, but the corrosion can spread into the inner fender if ignored. Clean, neutralize, and coat the area after battery replacement.
The rolled edges at the bottom of the front fenders catch stones and road debris. Small chips expose bare metal, and moisture does the rest. Check the leading edge where the fender meets the bumper, and the bottom curve near the door.
The body panel behind the rear bumper cover is hidden from view and rarely cleaned. Dirt and moisture accumulate there for years. Remove the bumper cover during inspection to check for surface rust or deeper corrosion on the bumper reinforcement bar and body panel.
Traditional rust repair requires multiple products: a rust converter, primer, color coat, and sometimes a separate rust inhibitor. WestNet One Stop Shop Paint Enamel simplifies the process with its 3-in-1 alkyd enamel formulation:
This means one product does the job of three, and at $19.99 per can, the cost is a fraction of multi-product systems. For underbody and hidden areas, WestNet Flat Black or Semi-Gloss Black provides a factory-correct finish with full rust protection.
Determine the extent of the rust. Surface rust (discoloration only) and scale rust (flaky but no holes) can be treated with paint. Through-rust (perforation) requires metal repair or panel replacement before painting.
Important: Do not paint over active, loose rust. All flaky material must be mechanically removed first. WestNet Paint Enamel prevents new rust formation but cannot bond to loose corrosion products.
Prevention is always easier and cheaper than repair. Follow this schedule to keep your MK3 Supra rust-free:
Canadian Winter Tip: If you drive your MK3 Supra in winter, wash the undercarriage at least weekly during salt season. One can of WestNet Flat Black applied to wheel wells and rocker panels before winter provides a full season of protection.
Rear wheel wells, rocker panels (sills), and the hatch seal area are the highest-risk locations. Battery trays, front fender lips, and the panel behind the rear bumper are also common. All of these areas trap moisture and road debris that accelerate corrosion.
WestNet One Stop Shop Paint Enamel includes built-in rust protection as part of its 3-in-1 alkyd enamel formula. When applied to properly prepared surfaces (all loose rust removed, surface sanded and degreased), it seals out moisture and oxygen to halt rust progression and prevent new corrosion.
No. WestNet One Stop Shop Paint Enamel combines paint, enamel finish, and rust protection. For small to medium rust repairs, it can be applied directly to sanded bare metal without a separate primer. For severe damage with extensive pitting, a skim of body filler may be needed before painting.
WestNet Flat Black is the best choice for underbody, inner fenders, and hidden structural areas. It matches the factory underbody coating and provides full 3-in-1 protection. For areas that were originally semi-gloss from the factory, use Semi-Gloss Black.
The alkyd enamel finish provides long-term protection when properly applied. In protected areas (underbody, inner fenders), a single application can last years. For exposed body panels subject to stone chips and UV, annual inspection and spot touch-up maintains the protective barrier.
WestNet One Stop Shop Paint Enamel — 3-in-1 paint, enamel, and rust protection in every can. Browse all OEM-matched Toyota colors.
Open Paint Selector