What is the plastic shell under the car trunk called?

[MaliaMarie]

The plastic shell under the car trunk is called the rear bumper. The car bumper is a safety device that absorbs and mitigates external impacts, protecting the front and rear parts of the vehicle body. More details are as follows: 1. Composition: It consists of three parts: the outer panel, buffer material, and crossbeam. The outer panel and buffer material are made of plastic, while the crossbeam is formed by stamping cold-rolled thin plates into a U-shaped groove, with the outer panel and buffer material attached to the crossbeam. 2. Function: The car bumper (anti-collision beam) is located in most areas of the front and rear of the vehicle. It is designed to prevent external damage from affecting the vehicle's safety system and has the ability to reduce injuries to occupants during high-speed collisions. Nowadays, it is increasingly designed for pedestrian protection.

[MaverickAnn]

As a seasoned driver who frequents repair shops, you're asking about that plastic panel under the trunk? We usually call it the rear bumper lower trim or rear diffuser. This seemingly insignificant part actually plays crucial roles: it protects chassis wiring from road debris and prevents mud/water backflow during rainy days. Last time I reversed into a curb, this thing cracked right in half. The dealership charged me over 200 yuan for replacement, and the mechanic said that was actually cheap - damaging the radar sensors behind it would've hurt much more. Now I always remind car wash guys to thoroughly clean the dirt trapped in its seams, as accumulated grit can warp the mounting clips over time.

[RoseFitz]

As regulars at the car modification shop, we all call that part the rear lip spoiler. Don't underestimate it as just a piece of plastic—the wind resistance coefficient design is quite meticulous. Last time when installing a sports kit on my Civic, I only noticed the four reverse radar sensors hidden underneath after removing the factory part. Nowadays, some new cars come with integrated rear bumpers, but most still have a split structure. If you're looking to upgrade it, searching for 'rear bumper lower guard' on Taobao will bring up tons of aftermarket parts. You can get an ABS one for around 500, while carbon fiber versions cost double. During installation, pay attention to aligning the gaps with the taillights—my friend didn't install it flush last time, and the rearview camera always made it look like there was a tail dragging behind.

[DominicMarie]

Having worked in the auto parts market for over a decade, this component is listed in our warehouse inventory as 'rear bumper lower guard.' In reality, it's not just decorative - its main purpose is to protect the exhaust pipe from damage caused by gravel kicked up by the tires. Last week, a BMW owner came in dragging a half-detached guard, asking if it could be welded. Plastic parts are quite brittle, and typically when the clips break, the entire piece needs replacement. The price difference between models is substantial - domestic cars might cost around a hundred yuan, while luxury vehicles with painted surfaces can run into thousands. I recommend supervising the installation - last time when ordering for a customer, I discovered the radar hole positions on the new guard were half a centimeter off from the original, forcing us to manually adjust the openings with a hot knife.

[DelJayce]

My car repair notes mention: The official name for the plastic component under the trunk is the lower rear bumper deflector. Last month during rainy weather, I noticed a splashing sound when driving through puddles. After lifting the car on a hoist, I discovered that the center of this panel was dented and holding water, with its drainage holes clogged by rotten leaves. While poking them open with a screwdriver, I also checked the mounting clips—three out of ten were broken. I bought stainless steel clips from Taobao to replace them, which turned out sturdier than the original plastic ones. This part is designed too close to the ground, making it prone to scraping on rough roads. My advice: slow down in advance when you spot poor road conditions.

[LeSilas]

When doing used car evaluations, you always have to bend down to check that rear bumper undercover. Once while inspecting a car, I noticed the edges of the undercover were whitish. Shining a flashlight revealed body filler marks inside, which led to discovering the car had been rear-ended. Regular owners can squat down occasionally to feel if the edge clips are loose, and use a soft brush to clean the drainage channels during car washes. Last time I saw an owner using self-tapping screws to secure a loose undercover, but it cracked in winter cold. If replacement is needed, remember to choose PP material, which is more cold-resistant than regular plastic. Nowadays some new energy vehicles use aluminum alloy undercovers instead, but most fuel cars still use this black plastic part as a consumable item.