Does Replacing the Trunk Lid with an OEM Part Require Painting?
4 Answers
Replacing the trunk lid with an OEM part requires painting because the original OEM trunk lid does not come with a painted surface. Therefore, it needs to be painted at the 4S shop before installation. Below is the relevant information: 1. The car's body paint is complex, consisting of four layers. From the inside out, they are the electrophoretic layer, the primer layer, the base coat layer, and the clear coat layer. 2. Each layer of paint has a unique application process and function. Details are as follows: (1) After the entire body is assembled, robots immerse the body in an electrophoretic tank, forming an electrophoretic layer on the entire body. The main function of the electrophoretic layer is rust prevention. (2) After the electrophoretic layer is formed on the body surface, robots apply the primer layer, which also serves to prevent rust and enhances adhesion to the next layer of body paint. (3) Above the primer layer is the base coat layer, whose main function is aesthetics. The various body colors we see are presented by the base coat layer. (4) The outermost layer is the clear coat layer, which protects the base coat layer and enhances its gloss. The clear coat layer is the most vulnerable paint layer, and most minor scratches typically remain on this layer.
As someone who often tinkers with my car, I once replaced the trunk lid with an OEM part, but it arrived as a bare metal panel with no paint. That's normal because manufacturers leave them unpainted to save costs. I had to take it to a professional shop for painting, which involved color matching to the car body, applying primer for rust prevention, then the base coat and clear coat. The whole process took about two days and cost around 800 yuan. Without painting, not only would the color mismatch look bad, but exposure to rain or dirt would quickly cause rust—especially in the humid trunk area! In the long run, skimping on paint isn't worth it. After painting, maintenance is key, like avoiding harsh scrubbing during car washes to keep the finish smooth. For beginners, I recommend clarifying the timeline, cost, and process upfront and choosing reputable shops to avoid scams.
I've been repairing cars for over a decade, and replacing an OEM trunk lid definitely requires painting—99% of cases are like this. The parts come bare, mainly due to standardized production. Color matching is crucial during painting, using the VIN code to mix the paint; otherwise, significant color differences can affect the car's appearance. Additionally, unpainted metal corrodes quickly when exposed, especially since the trunk area tends to accumulate water. Professional painting includes cleaning, sanding, primer, color coat, and protective layers, typically taking about a day and a half and costing around a thousand bucks. I recommend not skipping this step—find a reputable shop, or you might face peeling and rust issues later. DIY is an option, but make sure you have proper equipment, like a quality spray gun, or the results will be poor.
As an average car owner, after replacing the original trunk lid, I sent it directly for painting. The part itself comes unpainted and must be sprayed to match the car body. The process, simply put: the shop cleans the surface, applies primer, sprays the color coat, and finishes with clear coat—color matching is crucial. It cost a few hundred bucks and took a day. Without painting, the color mismatch would look awful and could lead to rust, shortening its lifespan. Just find a reputable shop.
