Just took delivery of my 2025 G63 last week and I've been wanting to do a OEM mud flap install since they don't offer this as a stand alone option from the factory unless you picked the Professional package (with the roof racks and ladders and all that).

While there's an older thread on installing this equipment on the '19~'24 models, as many have already reported, the ‘25 MY has different inner fenders which makes this process mildly more challenging. So I thought I'd share my experience here in case there are others looking to do the same.

Here's a picture of a '25 inner fender, notice that there's now only two holes (with existing screws), instead of 4 holes like on the previous MYs. I believe the change in the inner fender design and material from a plastic to a fuzzy, interior trim like material is to mitigate noise(?). It still has the same shape that conforms to the mud flaps molded in, just no more pre-drilled outer holes. Additionally, these outer holes will now be occupied with the plastic fender rivets instead of screws because there's nothing but empty space on the backside to screw into. Note that the inner two screws are structural and screws into metal brackets, while the outer two holes are only for securing to the inner fender, this aspect remains the same as the previous MY's.




So here's my process:

1. Unscrew the two 8mm hex bolts occupying the two inner screw holes and set them aside (or just toss them, you'll probably never need them again).

2. Locate the outer two holes by temporarily mounting the mud flap (using the two inner screw holes), then use it as a template to mark out the locations.

3. This is where things might get a bit more tricky, because there's really no room to fit a drill with the tire in the way, and this new fuzzy fibrous inner fender material is also pretty darn resistant to puncturing. I ended up using a soldering iron to melt through it and carefully circumscribed the hole with the hot iron until the desired diameter (about 1/4") is achieved. It's not a bad idea to make the holes slightly undersized so there's a healthy amount of resistance when inserting the fender rivets. Alternatively I think cutting an X with a blade also works. The goal is to make it so that the fender rivets can be pushed through by hand with some pressure.

4. Now that the two outer holes are made, we can finally mount the mud flaps for real. Start with the two outer holes, insert the fender rivet fully into each hole and squeeze the inner fender against the mud flap until everything is flush, then push in the rivet button to lock it in place. You can pull the inner fender out of the bumper slightly to make this process easier.

5. Screw in the two structural screws into the inner two holes, adjust the position of the mud flap to its "sweet spot" before tightening the screws down. make sure not to over tighten, I used an right angle drill set at the lowest torque setting for this. Once done, it should look something like this:

6. Repeat on the other side and walk around to check that both sides are symmetrical.

7. Here's how it looks installed:




Here are the parts I used:

x1 Mud Flap (RIGHT) 463-889-28-00-7C45
x1 Mud Flap (LEFT) 463-889-27-00-7C45
x4 Screws (for the inner holes) 000000-000925
x4 Fender Rivets (for the outer holes) 124-990-04-92

 

Awesome I was just wondering today if anything changed for the mudflaps. Thanks for the detailed write up and info.

It looks like the mudflaps are the same as the 2019-2024?

It still cracks me up how cheap the mudflaps are considering everything else about the G is so expensive.

 

Yes the mud flaps are still the same part number as '19~'24, I verified this with my local dealership's parts department by having them look it up in their system for 2025 and they came up with the same parts number as well.

And you're right about how cheap it is, sure mud flaps aren't the most exciting upgrade and people aren't exactly rushing to get theirs, but my total parts cost was under $100 including shipping and tax, and I'm ok with that .

 

Very good. Nice looking G by the way! I installed mudflaps in a 2022 MDX that had the same felt material. I’ll probably try an 11 blade x-acto or something similar and see if I can puncture the material.

 

Thanks! The pic of the red G63 you posted from the old thread pretty much sold me on installing the mud flaps on mine. Anyway, if I had to start over again I would try the blade method first before going nuclear with the soldering. Hope to see pics of your new G soon.

 

Wow MB deciding to do felt material in the wheel liner is bizarre

the mud flaps look great!

 

it‘s already attracting debris like a magnet.

 

Thanks again for the great post. I just installed the mudflaps but in a round-about way.

I took off the original screws and placed the mudflap as a template using the two middle new screws as stated. I then used an x-acto #2 blade to make cuts in the lateral holes. The x-acto knife goes through the fabric like butter but it only does a slice at a time, so I kinda made cuts like I was cutting pizza. I tried the rivets but no luck.

I took off the mudflaps and it was easy to see where I had made cuts, so I made a few deeper cuts with the mudflap out of the way but still no luck with the rivets.

Since the original screws are tapping screws with a sharp end, I then tried to use them to create an opening for the rivets, but once I was able to break through, I realized the original screws were screwing in tightly through the fabric. I decided then to abandon the rivets and use the original screws for the lateral positions, and it works.

 

Excellent work around! "Theoretically" the rivets should offer a more secure hold for thin pieces, but at the end of the day those two outer hole positions are just there to "button things up" as opposed to the inner two screws which are actually structural, so if it works it works!

The mud flaps, aside from its practical function, just gives the G that much more robust, utilitarian look doesn't it. Dare I say that it may even look a bit naked without it now that I'm so used to having them. Oh and congrats on taking delivery of your Dark Olive G63! really beautiful color.

 

I'm guessing you can drill the holes if you pull the wheel off. I installed a set on my '19, and agree they don't look much different than having been cut from a door mat, except being thinner. Still waiting for a set of fronts to become available.

 

Frankly if they haven't come out with a front set by now it's probably not gonna happen for this generation.

 

Thanks! I agree the rivets are preferred and a much cleaner install. For mine the screws are flush but they don't give the satisfying "locked into place" feeling as the screws just turn on forever.

For me the mud flaps are very functional to keep the side rear bumpers cleaner, and the fact that they make it look more utilitarian is a bonus! Plus for like $35 how can you go wrong lol.

 

Fantastic write-up. I just ordered my setup. Mudflaps are a must on a G, imo. We have a heavily worn set on the front and rear of our 82 SWB.

For those who have installed these after the OP: did you use all screws, all rivets, or a mixture of both (as OP did)?

 

This is awesome, I wanted mud-flaps and you’ve answered all my questions without me even asking. Thank you! Sweet spec BTW, your G looks wicked!