New Zealand has one of the highest concentrations of classic JDM cars outside Japan. R32, R33, and R34 Skyline GT-Rs. S13, S14, and S15 Silvias. A80 Supras. FD RX-7s. Evo VIs through IXs. These cars are now 25 to 40 years old, many with original paint that's been through decades of Japanese road salt, New Zealand UV, and varying levels of care. Detailing them requires a fundamentally different approach than working on a modern car.
What Arrives from Japan
Most JDM imports land in New Zealand carrying specific contamination from Japanese conditions. Japanese roads are heavily salted in winter, particularly in Hokkaido and northern Honshu. That salt causes iron contamination that embeds into paint at a molecular level — it's invisible until you spray iron fallout remover and watch the surface bleed purple.
Hard water mineral deposits are the other major issue. Japan's water is mineral-rich, and decades of car washes leave calcium and silica deposits etched into the clear coat. These appear as white hazing or water spot rings that don't come off with normal washing. On a white R33 they're hard to see; on a Midnight Purple R34 they're devastating.
Then there's the general road grime. Japanese domestic cars rarely get detailed to the standard New Zealand enthusiasts expect. Many spent years parked in tight Japanese car parks accumulating door dings, shopping trolley marks, and general neglect. The paint is tired.
The Paint Thickness Problem
This is where JDM detailing gets serious. Japanese manufacturers in the 1990s applied thinner clear coat than their European counterparts. A typical R32 GT-R has 80 to 110 microns of total paint (primer + base + clear), compared to 120 to 150 microns on a contemporary BMW or Mercedes. Some panels — particularly those that have been repainted in Japan — can be even thinner.
Why does this matter? Paint correction (machine polishing) works by removing a thin layer of clear coat to level out scratches and swirl marks. On a car with 40 microns of clear coat, you might have 10 to 15 microns of safe working depth. That's enough for one or two careful corrections across the car's lifetime. Aggressive cutting or multiple correction sessions will burn through the clear coat entirely, leaving you with a panel that needs repainting.
Before any machine touches the paint, we take paint depth readings across every panel with an electronic gauge. This tells us exactly how much clear coat we have to work with — and whether correction is even safe on that panel.
Single-Stage vs Clear Coat Paint
Many Japanese cars from the mid-1980s and earlier used single-stage paint — where the colour and protective layer are mixed into one coat, with no separate clear coat on top. Some early 1990s models used it too, particularly on economy trim levels.
Single-stage paint behaves differently under machine polishing. It's softer, it generates colour transfer onto your polishing pad (which is normal — you're cutting into the colour layer), and it oxidises more readily. The polishing technique needs to be less aggressive: lower speed, softer pad, finer compound. You cannot use the same approach you'd use on a modern two-stage clear coat without causing damage.
If you're not sure whether your car has single-stage or clear coat paint, a simple test: wipe a small hidden area with a damp white cloth. If the cloth picks up colour, it's single-stage.
Models That Need Special Attention
R32/R33/R34 Skyline GT-R
Nissan's factory paint on these generations is notoriously soft and thin, particularly in dark colours. Midnight Purple (LV4) on the R34 is famously delicate — the metallic flake is close to the surface and can be dulled by aggressive polishing. BNR34 values now exceed $200,000 for clean examples, so a botched correction is an expensive mistake.
S13/S14/S15 Silvia
These tend to arrive with more wear than GT-Rs because they were cheaper cars in Japan, often driven harder and maintained less. Expect thinner paint on high-wear areas (front bumper, bonnet, roof) and potentially multiple repaint layers from Japanese panel shops. Paint depth readings are essential before correction.
A80 Supra (JZA80)
Toyota's paint on the A80 is generally tougher than Nissan's equivalent era, but the factory clear coat still doesn't compare to modern standards. Super White (040) is common and forgiving; Renaissance Red (3L2) is harder to correct without introducing holograms.
FD RX-7
Mazda's paint on the FD is middle-of-the-road for the era. The main challenge is the bodywork: highly curved panels with tight radii that make machine polishing technically demanding. Inexperienced detailers frequently burn through edges on the FD's aggressive fender arches.
What a Proper JDM Detail Includes
- Full decontamination — iron fallout removal (critical for Japanese imports), clay bar treatment, tar and adhesive removal from Japanese dealer stickers and inspection markings.
- Paint depth measurement — electronic gauge readings on every panel. This determines what level of correction is safe and identifies panels that have been repainted.
- Conservative correction — using the least aggressive approach that achieves acceptable results. On thin paint, this often means a single-stage polish rather than a two-stage cut-and-polish. The goal is 80 to 90 per cent defect removal, not 100 per cent — preserving clear coat is more important than chasing perfection.
- Interior restoration — Japanese interiors accumulate specific wear: sun damage to dashboards (many JDM cars have right-side sun damage), cigarette smoke residue (smoking rates in Japan are higher), and wear on Alcantara or suede trim common in GT-R and Type R models.
- Protection — ceramic coating is the preferred finish for classic JDM. It provides long-term UV protection without the ongoing maintenance of wax, and it doesn't need to be removed and reapplied — which means fewer future opportunities for contact damage.
Why Preservation Matters More Than Perfection
These cars are appreciating assets. An R34 GT-R with original paint — even if it shows some age — is worth significantly more than one that's been repainted. The goal of detailing a classic JDM import isn't to make it look factory-new. It's to make it look the best it can look while preserving as much original material as possible.
That philosophy guides every decision: which compound to use, how many passes on each panel, whether a scratch is worth chasing or better left alone. It's a different mindset from working on a brand-new daily driver, and it's why these cars deserve a detailer who understands what's at stake.