Every car that comes in for ceramic coating or PPF at DRVNZ goes through a pre-delivery inspection before any product touches the paint. This step isn't visible in the finished result — by the time the car leaves, it just looks exceptional. But what happens in the inspection determines whether the result is exceptional or merely adequate.
Here's exactly what we're doing and why.
Step 1: Visual assessment under controlled lighting
The first thing we do is move the car into our inspection bay and assess the paint under high-intensity lighting — raking light that reveals surface defects invisible in normal ambient or outdoor conditions.
What we're looking for at this stage:
- Swirl marks from previous washing (very common on cars that have been through automatic washes)
- Fine scratches from wipe-downs with the wrong cloth or technique
- Haze in the clearcoat — early UV oxidation
- Water spot etching from previous monsoon damage or mineral-rich water
- Any existing paint work — touch-up, respray, or filler — that changes our approach to that panel
This lighting assessment takes 20–30 minutes on a full car. We document what we find. For a new car from the dealership, we're typically seeing minor transit or storage marks — manageable with light correction. For a 3–4 year old car, we frequently find more significant swirl marks and potential water spot etching that needs addressing.
Step 2: Paint depth gauge measurement
We measure paint depth across the major panels with an electromagnetic paint depth gauge. This gives us two things.
First, it tells us if any panels have been repainted. Original factory paint typically reads 100–150 microns. A repainted panel often reads 200–300 microns or more (the additional layer of repair paint and clearcoat). Knowing which panels are original and which have been repaired informs our correction process — repainted panels have different hardness characteristics and require different correction approaches.
Second, it tells us how much clearcoat we have to work with for correction. Paint correction removes a small amount of clearcoat to level the surface and eliminate scratches and swirl marks. Knowing the starting depth ensures we don't over-correct and leave insufficient clearcoat for the coating to bond to.
Step 3: Decontamination wash
Before any correction or application work, the car gets a thorough decontamination wash. This is different from a normal wash — it's a multi-stage process designed to remove all bonded contamination from the paint surface.
The stages:
- Pre-rinse: high-pressure rinse to remove loose surface contamination
- Snow foam: pre-wash foam applied and left to dwell, loosening bonded contamination
- Contact wash: pH-neutral shampoo with a clean wash mitt, panel by panel, using two-bucket method
- Iron fallout removal: iron decontamination spray applied to all panels — iron particles from brake dust and road debris bond to paint and cause rust specks visible as tiny brown dots. The iron remover dissolves these chemically. The colour change (clear to purple) tells us where the contamination was.
- Clay bar treatment: clay bar removes any remaining bonded contamination that chemical treatment didn't address. The clay picks up everything the wash and iron remover left behind.
- Final rinse and panel wipe: rinse with filtered water, dry with clean microfibre, panel wipe with isopropyl alcohol solution to remove any residual oils or lubricants from the clay process
After this sequence, the paint surface is clean at a level that normal washing cannot achieve. Any contamination left on the surface when coating is applied will be locked in permanently. This decontamination step is non-negotiable.
Step 4: Paint correction
Based on what the lighting assessment and gauge measurements showed, we now correct the paint. This means machine polishing — using a dual-action or rotary polisher with appropriate compound and pad combinations — to level the clearcoat surface and remove the scratches, swirl marks, and haze identified in step 1.
For a new car with only minor transit marks, this is typically a light one-stage polish taking 1–2 hours. For a car with significant swirl damage, it might be a two-stage process — cut first with a more aggressive compound to remove the defects, then refine with a lighter polish to restore the gloss. For cars with deep scratches or established oxidation, the process is more involved.
After correction, we wipe the panels again with IPA solution to remove any polish residue. The paint must be completely clean and free of oils before the coating goes on — any residue will prevent the coating from bonding to the surface properly.
Step 5: Final pre-application check
Before the coating or film goes on, we do one final check under the inspection lighting. The goal is to confirm that the correction is complete and the surface is clean.
This is also when we confirm the application plan for PPF — which zones are being covered, how the film will be routed around panel edges, and any specific areas that need particular attention based on the car's geometry.
Only after this final check do we begin application. By this point, the car has been in our care for several hours and the paint is in the best condition it's been in since it left the factory. What goes on top of that is the coating or film — the visible result the customer will see. But the result is only possible because of what came before it.
Frequently Asked Questions
How long does the pre-delivery inspection take at DRVNZ?
The full inspection and decontamination process — lighting assessment, paint depth measurement, multi-stage decontamination wash, iron removal, and clay bar treatment — typically takes 3–4 hours for a mid-size car before any correction or application work begins. For cars with significant correction requirements, the total preparation time before coating application can be a full day.
Why is paint correction necessary before ceramic coating?
Ceramic coating amplifies the paint's condition — it doesn't hide defects. Swirl marks, fine scratches, and haze under a high-gloss ceramic coating become more visible, not less. Correction removes these defects before the coating locks them in permanently. On a soft European luxury car finish especially, applying coating over uncorrected paint produces a result that looks worse than uncoated corrected paint.
What is iron decontamination and why is it important before PPF?
Iron decontamination uses a chemical solution to dissolve iron particles — from brake dust and road debris — that have embedded in the paint surface and begun to oxidise. These particles are invisible to the naked eye but create microscopic rust spots that bond through the paint layers over time. Before PPF application, iron removal ensures the surface under the film is completely clean. Iron particles left under PPF continue to oxidise and eventually show through the film as small brown spots.