This is a very common issue with GD cars with and without front lip spoilers. (Click the link and check out the pictures in my second post for more info.)
The down-force the front lip generates seems to be too much for the stock plastic bumper to handle, and cracks develop on each side of the opening in front of the radiator. After a few unsuccessful attempts to fix this issue with super strong glue, I decided to do it right and invest in some Bondo Fiberglass Jelly and fiberglass fabric to fix this once and for all.
By the way; Bondo Fiberglass Jelly + Fiberglass cloth is specifically meant to be applied to plastic and surfaces which are subject to flex. Regular Bondo is not meant to be used on plastic.
Supplies:
-Respirator/face mask
-Eye protection
-Nitrile Gloves (my personal preference)
-Acetone (Home Depot/Lowes)
-Rags
-Scissors
-Non-porous surface to mix the bondo and hardening cream. This can be pretty much anything plastic.
-Something to stir the bondo with when you mix in the hardening cream. I used a piece of scrap wood that doubled as my scooper.
-2 Cheap-O 1" paint brushes
-Bondo Fiberglass Jelly (Should come with Hardening Cream under the tall plastic lid)
-1 pack of Bondo Fiberglass Cloth
-60 grit sand paper
-jack (to raise sagging bumper before the Bondo process)
-Beer!
Procedure:
1) You will want to begin by getting the front end of the car off the ground so you have space to work under there (Ramps, Jack Stands, etc).
2) Place your jack (I used a bottle jack) under the center of the bumper and raise it so the cracks close up and are nice and tight. You do not need to remove your front lip as there is enough space behind it for the jack. If you use a bottle jack you'll need a block of wood or something under it so it can reach the bumper.
3) Next, get your sand paper and really scrape the greater area around the crack. You want a good area to be scored so the bondo adheres to the plastic. The space is somewhat tight so I removed three of the plastic plugs that hold the undertray in front of the front wheels so I could get my arm in there better. You can see the undertray hanging down in the photo below.
Picture of the scored area (Red circle is scored area, cracked area is inside yellow circle):
![Image]()
4) Put your gloves on, grab a rag, soak it in Acetone, and wipe down the areas that you just scored. Keep using fresh rags w/ Acetone until the rags are clean after you wipe the areas. Now the area is clean and ready for the Bondo. Hooray!
Before doing this next step, be sure that your face mask, eye protection, and gloves are on. If you breath in the Fiberglass particles that get all over the place from cutting the fabric, they will remain in your lungs FOREVER. Try to cut the fabric in a still area out of the wind
5) Cut your fabric into 2" wide x 3" long strips. I used three strips per side.
![Image]()
6) Scoop out a golf ball sized amount of Bondo and mix it with a 1-1/4" line of hardening cream on your mixing area. Mix really well until the color becomes uniform and then immediately press a fiberglass fabric strip into the mix; completely coating one side of the strip with a thick amount of Bondo. Apply the coated strip over the crack and press it smooth against the bumper with your fingers. VERY QUICKLY, proceed to do this with the next two strips; placing them on and around the crack to create a patch that extends past the crack in all directions.
By the time you get done the third strip the Bondo will be too hard to use and you'll have to mix up another batch for the other side. Be sure to set up your supplies so you can be under the car where you need to work and be able to mix/apply the strips. The bondo hardens ultra fast!
Picture of the fabric strips applied (Looks messy, but the second coat will take care of that):
![Image]()
7) Once your strips have been applied to both sides of the bumper, mix up another batch of Bondo and use your paint brush to apply a thick coat over the fabric strips. Really cover the area well; you shouldn't be able to see the fabric at all when you're done. Again, you will need to make one batch per side and you'll need a fresh brush for each side.
8) Let everything harden over night before removing jack if possible.
That's it! I drive between 80-100mph daily and it is holding up well. I did this in May 2012 and hopefully this will prove to be a durable fix in the long run.
Enjoy!
The down-force the front lip generates seems to be too much for the stock plastic bumper to handle, and cracks develop on each side of the opening in front of the radiator. After a few unsuccessful attempts to fix this issue with super strong glue, I decided to do it right and invest in some Bondo Fiberglass Jelly and fiberglass fabric to fix this once and for all.
By the way; Bondo Fiberglass Jelly + Fiberglass cloth is specifically meant to be applied to plastic and surfaces which are subject to flex. Regular Bondo is not meant to be used on plastic.
Supplies:
-Respirator/face mask
-Eye protection
-Nitrile Gloves (my personal preference)
-Acetone (Home Depot/Lowes)
-Rags
-Scissors
-Non-porous surface to mix the bondo and hardening cream. This can be pretty much anything plastic.
-Something to stir the bondo with when you mix in the hardening cream. I used a piece of scrap wood that doubled as my scooper.
-2 Cheap-O 1" paint brushes
-Bondo Fiberglass Jelly (Should come with Hardening Cream under the tall plastic lid)
-1 pack of Bondo Fiberglass Cloth
-60 grit sand paper
-jack (to raise sagging bumper before the Bondo process)
-Beer!
Procedure:
1) You will want to begin by getting the front end of the car off the ground so you have space to work under there (Ramps, Jack Stands, etc).
2) Place your jack (I used a bottle jack) under the center of the bumper and raise it so the cracks close up and are nice and tight. You do not need to remove your front lip as there is enough space behind it for the jack. If you use a bottle jack you'll need a block of wood or something under it so it can reach the bumper.
3) Next, get your sand paper and really scrape the greater area around the crack. You want a good area to be scored so the bondo adheres to the plastic. The space is somewhat tight so I removed three of the plastic plugs that hold the undertray in front of the front wheels so I could get my arm in there better. You can see the undertray hanging down in the photo below.
Picture of the scored area (Red circle is scored area, cracked area is inside yellow circle):
4) Put your gloves on, grab a rag, soak it in Acetone, and wipe down the areas that you just scored. Keep using fresh rags w/ Acetone until the rags are clean after you wipe the areas. Now the area is clean and ready for the Bondo. Hooray!
Before doing this next step, be sure that your face mask, eye protection, and gloves are on. If you breath in the Fiberglass particles that get all over the place from cutting the fabric, they will remain in your lungs FOREVER. Try to cut the fabric in a still area out of the wind
5) Cut your fabric into 2" wide x 3" long strips. I used three strips per side.
6) Scoop out a golf ball sized amount of Bondo and mix it with a 1-1/4" line of hardening cream on your mixing area. Mix really well until the color becomes uniform and then immediately press a fiberglass fabric strip into the mix; completely coating one side of the strip with a thick amount of Bondo. Apply the coated strip over the crack and press it smooth against the bumper with your fingers. VERY QUICKLY, proceed to do this with the next two strips; placing them on and around the crack to create a patch that extends past the crack in all directions.
By the time you get done the third strip the Bondo will be too hard to use and you'll have to mix up another batch for the other side. Be sure to set up your supplies so you can be under the car where you need to work and be able to mix/apply the strips. The bondo hardens ultra fast!
Picture of the fabric strips applied (Looks messy, but the second coat will take care of that):
7) Once your strips have been applied to both sides of the bumper, mix up another batch of Bondo and use your paint brush to apply a thick coat over the fabric strips. Really cover the area well; you shouldn't be able to see the fabric at all when you're done. Again, you will need to make one batch per side and you'll need a fresh brush for each side.
8) Let everything harden over night before removing jack if possible.
That's it! I drive between 80-100mph daily and it is holding up well. I did this in May 2012 and hopefully this will prove to be a durable fix in the long run.
Enjoy!
