Rear Bumper Lips for Nissan 350Z Z33

Rear bumper lips extend the lower edge of the rear bumper, and bumper caps fill out its corners. They lower the visual line at the back, help tidy the air leaving from under the car and complete a set with a front lip. Polyurethane is the usual material, and each part is listed for a specific model.

Air that has travelled under the car leaves at the rear bumper and mixes into the wake. A true diffuser slows this flow gradually in an expanding channel, and that pressure recovery lets the air under the car run faster and at lower pressure. It needs a fairly flat floor ahead of it, so on most road cars a diffuser-style lip changes the wake and the look more than the downforce.

Clearance still matters at the back, even if less than at the front. A low lip can catch on ramp exits, steep driveways and trailer ramps, and a loaded boot lowers the tail further. Corner caps also shield the bumper corners, which take most parking knocks.

The listings differ in three ways:

• Lip, caps or diffuser: a full lip runs under the whole bumper, while corner caps extend only its sides. A diffuser-style lip imitates a race diffuser.
• Model and body: match the model, years and door count to your car, as two-, three- and four-door bumpers of one generation can differ.
• Style: factory sport, OEM-style and tuner-inspired designs.

Trial-fit the part and leave a clear gap to the tailpipe, because polyurethane softens near exhaust heat. Fix it with screws into the bumper edge plus a flexible adhesive along its face, and keep the rear towing point and any parking sensor clear.

Polyurethane shrugs off a light knock instead of cracking, but its paint has to bend with it. Use a flexible primer with a flex additive in the colour coat, and inspect the screws after any heavy contact.