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Product Review: Gtechniq C4 Permanent Trim Restorer


KMG - C4

Nothing makes all your hard work after perfecting the paint look more incomplete then old faded trim.  I seem to have a weak spot for trying lots of different trim coatings, and I must say that Gtechniq C4 Permanent Trim Restorer certainly has become one of my favorites to use since trying it.  As with most of the trim coatings on the market, C4 is claiming a durability of roughly 24 months.

Product Description

Gtechniq C4 is not just your regular trim coating, it will bond to your trim restoring it to like new condition with ease! Most trim restorers or protectants are shiny coatings that sit on top of the plastic and they only provide temporary shine and color restoration. C4 actually swaps part of its molecular structure with the surface molecules of your car’s trim! This allows the C4 to keep your trim looking brand new for up to two years! Use C4 on trim, weather stripping, plastic mirrors, battery covers, hoses, etc. If you are looking to restore your trim to like new condition grab a bottle of the C4 Permanent Trim Restorer today!

Application Information

  • Do not dilute
  • Apply at a temperature above 40 degrees F and not in direct sunlight
  • If applying indoors ensure that there is adequate ventilation and wear protective gloves
  • Ensure that the surface to be coated is entirely free from fats/oils or previously applied products
  • Use the lint free application pads supplied to spread the coating onto the trim
  • Because the coating forms its bond immediately it is very important to remove excess coating from the treated surface and any that has gone onto the vehicles bodywork or glass within 5 minutes of application
  • To remove residue, use a clean microfiber cloth

Pictured below is cowl trim piece on a Porsche Boxster, and you will notice how faded or aged it looks.  Over time with exposure to the sun all trim will begin to look like this if not properly cared for and protected.  This is where a product like Gtechniq C4 is perfect.

KMG - C4

To begin the application, you will want to thoroughly clean the trim.  I like using Einszett Plastic Deep Cleaner, as shown in my previous blog on this product.

KMG - C4

Application is quite simple with C4.  Included in the kit is everything you will need to use, including cotton applicators that will be used to apply the product.  You will apply a small amount of coating on the applicator to start applying.  A small amount will go a long way when using this product, and you will want to be sure that you are applying the product evenly.

KMG - C4

You can see that once dried the product will drastically darken the trim leaving a dark, rich sheen on the trim.

KMG - C4

The rear bumper guards also were in poor condition and needed some attention. These were cleaned just like all the other trim pieces before applying the coating.

KMG - C4

For the application of C4 on these, I preferred to use a detailing swab as this was easier to get into the tighter spaces recessed into the bumper cover.

KMG - C4

As with the cowl trim, you can see that the dark color has been restored to the piece and should remain for upwards of 2 years.

KMG - C4

The one on the left is cleaned and has the coating applied, while the one on the right is still in the condition that the car arrived in.

KMG - C4

If you are wanting a product that is extremely easy to use that will darken and protect your trim for years, not weeks or months then you will certainly want to give Gtechniq C4 a try.

Kevin M. George
KMG Detailing
Lebanon, PA

19 comments on Product Review: Gtechniq C4 Permanent Trim Restorer

  1. Zach says:

    Simple and informative review. I love reading review like this one. I was curious, is there any benefit to multiple coats? Can you achieve an even darker finish if applied heavy?

    • Kevin George says:

      Zach, I am glad you enjoyed the review. I am not sure there is much benefit to applying multiple coats. It might get slightly darker, however I am have not tried it as the trim in most cases is a nice deep rich color after just a single application.

  2. Mike says:

    Great review. Which do you prefer between this or DLUX?

    • Kevin George says:

      Mike, I am currently working on an article that will compare 22ple VR1, DLUX and Gtechniq C4. I will go over the strengths and weakness of each. Both work great, however I think that C4 is a bit easier to apply. Watch for my future post on this topic. Thanks!

  3. Michele says:

    Thanks for reviewing this product! One question: What did you use to clean/prep the areas prior to applying C4? I still have some residual Solution Finish on parts I want to try C4 on. It’s pretty oily.

    • Kevin George says:

      Michele, I will usually clean the trim really well during the wash process with APC and a brush or bug sponge. The once the vehicle is dry I like to clean the trim one last time with Einszett Plastik Reiniger Plastic Deep Cleaner and a microfiber towel. At this point you should have a nice clean surface to apply the coating on.

  4. Pete says:

    I have a challenge and need some expert advice. I recently purchased a 2011 vehicle that someone sprayed what appears to be a soapy product onto the plastics under the hood. Unfortunately, there now is a white residue on nearly all the parts where it wasn’t rinsed and the vehicle as driven after it dried. I have tried a variety of cleaners including isopropyl alcohol to no avail. Would the Gtechniq product work or other suggestion?

  5. Kevin George says:

    Pete, this may be difficult to help with being that we are not certain what they actually used on the trim. Depending on what they used it could have stained the trim and possibly may not come out. I would actually give Solution Finish a try as that may work better in this situation. Hopefully that will work for you.

  6. Robert McCarty says:

    Could you add the CarPro plastic coating in your review? CarPro plastic coating seems to get the most attention and I would be interested in knowing which one is easier to apply. Thanks.

  7. Robert McCarty says:

    My mistake Delux is the CarPro offering. When do you think you will have the results of your tests?

    • Kevin George says:

      Robert, I am hoping to have something put together in the next week or two. However it will be up to Reece as to when the article would be posted. Thanks again.

  8. Danny says:


    The white substance could possibly be straight car wax. It us very tough to remove.

    I know, I got some on a textured surface and I tried a lot of things you normally wouldn’t use – but it is wax and it’s job is to protect and it takes its job seriously.

    Try a stiff scrub brush and a wax cutter.

    As a last redory, A very light coat of gasoline and an application of a match followed by a quick scrubbing should do it. Hahaha

    • jeff groner says:

      sounds like the meguires in the spray can,its like a semi perm plastic coating,black can with yellow car on it,it does that when it gets old in age,whitash ,nothing takes it off

  9. Tyson says:

    I’ve got a 84 911 with the black anodized trim. The black anodizing is in decent condition but I’d like to prevent it getting worse and potentially nake it look better in the process. Would C4 work or is it stricly for plastic? What would be best if C4 wouldn’t work?

    • Kevin George says:

      Tyson, sorry I some how missed your question when you posted it. C4 would work on the trim pieces just fine, however something like Crystal Serum Light would likely be more durable and last longer.

  10. Denzel says:

    What happens to the trim after 2 years from using C4, will the plastic crack.

    • Kevin George says:

      Denzel, trim coatings won’t have a negative effect on the trim. As the product begins to diminish it will likely no longer bead water or possibly begin to fade again. I have used many different trim coatings on clients vehicles and my own personal vehicles, and honestly pretty much all of them have lasted far longer then the stated length of durability.

  11. Laurie says:

    I apologise for a late question but I’m just doing a restoration and looking for a good product to use on my car seats. All the reviews talk about applying GTechniq to trim, does this include vinyl seat covers? if not what would you recommend ?

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