DIY Installing a Rear Factory Original Decklid Spoiler

I wanted to use my Infiniti dollars to purchase an accessory, unlike my first option of illuminated side sills that are seen for perhaps the 30 seconds that door are open at low light, the deck lid is visible always to everyone, so I decided to change the look of the rear to stand out from the more and more Q50s hitting the road.

At the end of the day this spoiler is purely aesthetic and had no performance gains; but I think Infiniti did a good job designing the spoiler and I liked the crisp and clean look that adds a little subtle flare to the rear without being overly obnoxious. It also does not require changing the gas shocks of the trunk.

I bought the spoiler, pre-painted and color-matched from my local Infiniti parts department. It came in 2 days and I decided to do the install myself. It came in a considerably big and protective box, and a single sheet of paper that refers to the online site of TechInfo where the factory instructions are available.

Rear Spoiler Installed

I will point out that the instructions require 4 holes to be drilled from the outside of the trunk. The instruction also require 2 large holes to be drilled from the inside to allow for a 10mm socket reach the nuts to tighten them. I found a way that requires patience but does not require drilling the 2 larger holes in the trunk.

An option is to simply grind off the studs of the spoiler and use 3M double sided tape to install the spoiler much like door guards on other vehicles. I believe that with hot/cold temperature variations, water from rain, car washes, snow, etc. and finally the force of closing the trunk via the spoiler may in the long run make the spoiler fall off. I took the cautious approach but ensured that the wholes were properly treated to avoid rust.


Here are Tools that were needed:

- Racket, Socket, 10mm socket
- Masking Tape
- 10mm wrench
- Dremmel with de-burring bit
- Center Punch and Hammer
- Rubbing Alcohol
- Power Drill with 1/8" and 7/16" metal drill bits
- Anti-rust (bitumen wax) Wax
- Color Matched touch up paint
- Magnetic pickup
- Twine or string

Tools for the Job

Step 1: Remove the Inner Trunk Liner

Trunk Liner Removal

Remove the Emergency release handle
Remove the handle plastic tray
Remove the Spring bumpers
Remove the retainer clips
Remove the entire inner trunk liner.

Liner Removed

Step 2: Attach the included template to the trunk lid.

Get pieces of masking tape ready.

Lots of masking tape

Starting at one end tape the template to the trunk using the instructions printed on the template

Attaching Template

Make sure the center is aligned

Take time to do and redo the template until it is even and perfect. There is no do over after the holes have been drilled.

Template Attached and Aligned.

Put some masking tape under the template and mark the "Z-directional" lines on the tape. Once the template is removed these 2 pieces of tape will stay on until the spoiler is installed.

Z direction masking tape under template

Step 3: Make the 4 holes for the spoiler.

Using the center punch and hammer make the 4 required dimples in the trunk. These will help the drill bit stay in proper position.

Center punch, light tap.

Now remove the template from trunk but leave the Z directional masking tape

Punch Marks Made, Z-direction tape still on, Template Removed,

Very Carefully drill the 1/8" pilot holes using a high speed and steady hand. Making sure to only go through 1 layer of metal, not the inner trunk material.

Drilling Pilot Holes

Make the 1/8" holes bigger by drilling the 7/16" holes.

Drilling Actual Size Holes 

Step 4: Protecting the holes.

Using the dremmel de-burring tool, remove all metal burrs.

Using the vacuum cleaner, clean up the holes

Using the rubbing alcohol, clean the inside and outside around the holes.

Using the touch up paint, re-pint the insides of every drilled hole. Allow this to dry (15 mins) and add another layer, then allow it to dry (30 min). Finally apply some anti-rust (bitumen) wax to each hole.

Step 5: Installing the spoiler

Clean the surfaces of the trunk where the spoiler will have the adhesive tape of the spoiler applied to the trunk. Using rubbing alcohol is best to remove any dirt, wax, etc to allow the adhesive to make good contact.

Test Install the spoiler's nuts into the holes. 2 of the nuts are nuts are adjustable and make sure to align the z-directional lines on the masking tape.

Test fitting and centering spoiler.

Make sure the spoiler is centered and the gap is even on both sides of the trunk. Slightly pull the spoiler back and remove the double sided tape cover from the edges of the spoiler.

Now press the spoiler to the trunk for 15 seconds using a micro-fibre cloth. If the outside temperature is below 60F, using a hair dryer to around the tape.

Remove the z-directional masking tape.

Now remove the 2 upper remaining 3M tape covers by peeling them along gently from the spoiler and again use pressure for 15 seconds to make the adhesive stick to the trunk. Again using a hair dryer to warm up the tape if needed.


Step 6: Installing the spoiler nuts.

Open the trunk and hand thread the 4x 10mm nuts to the 4 studs.

The middle 2 studs are easily assessable and tighten, but not over-tighten.

Center Stud

However, 2 of the corner studs are hidden behind the metal frame of the trunk.

Left Stud

Right Stud

At this point the Infiniti instructions require that 2 big 30mm holes are drilled to allow for a socket to be inserted. However, I ddi not want to drill 2 more wholes that would need to be rust protected, not to mention that metal hole saws are expensive. So, this is where I chose to stick my hand through one of the openings and reached studs to work the nuts onto the suds.

To finally tighten these bolts, I tied a string to a thin 10mm wrench with closed/open end. This is to allow to get the wrench when it drops into the trunk (which it did a few times). Working the wrench through the whole, moving it 45 degrees at a time, pulling it out of another hole and repeating the process a dozen times go the nuts tight enough.

Maneuver Wrench Left Side

Maneuver Wrench Right Side

Step 7 Final Assembly.

Remove all tools and items.

Replace the Inner Trunk liner, pass through the emergency release handle and snap into place.

Replace all retainer clips,  replace spring bumpers, and replace plastic handle.

Close trunk and clean, and buff the spoiler.

Final Results:

Side by Side comparison of before and after.

Rear View with Spoiler