CF Diffuser install issues

[Noggie]

Guys, need some advise.

I got a rear diffuser on eBay from a Taiwanese company that came recommended on a facebook group.
I will say that the sales ad did say that fitment may not be 100% and that professional installation was recommended.

Well, I just spent a couple of hours with a dremel tool and removed excess carbon fiber here and there and freshen up the tabs that clip into the bumper.

I have noticed that the fitment is not 100 in the two lower corners, and that it will pull a little on the bumper, but all in all I think it could fit.

But, there is a but, a kind of major issue. I have the kick to open trunk feature, and the antenna bracket that run along the whole bumper appears to come just far enough down that the diffuser won't fit.
Basically the curvature of the diffuser hits the bracket before it gets high enough for the center tabs to get to the place it needs to clip into the bumper.

Anyone solved this issue? looks like that bracket runs all the way up the back of the bumper and is not something that will come off easy or that it can be cut enough to give enough room.

Im talking about the piece circled in white on the picture.

[Dwaynos]

I'm not 100% sure but I would say that would either need to be removed, which would probably cause comfort access issues or fault codes, or purchase a diffuser that is made to suit cars with the kick opener, either way the kick opener will not work and need to be coded out, even with the genuine m performance diffuser.

Coding it out might stop it from showing a fault if you removed it but you'd just have to try it.

[Noggie]

Originally Posted by Dwaynos

I'm not 100% sure but I would say that would either need to be removed, which would probably cause comfort access issues or fault codes, or purchase a diffuser that is made to suit cars with the kick opener, either way the kick opener will not work and need to be coded out, even with the genuine m performance diffuser.

Coding it out might stop it from showing a fault if you removed it but you'd just have to try it.

I was afraid of that, I will give it one more go with some help, sometimes an extra pair of hands will help.

Also bought a Vorsteiner style front lip, I tied to hold it up to the front bumper and fitment appears to be miles off.
Think I will return this one to Taiwan for sure, not sure they will take the diffuser back after I've grinded on pretty much the whole thing

[Larry77]

Too late now, but I would never buy something like this on Ebay. If you end up looking for different parts, check out RW Carbon, I just installed their rear diffuser and fitment was very close (only had to trim one of the tabs). Not sure why but it isn't letting me add a hyperlink, just search "RW Carbon". They actually will talk you through the install, they are in Cali, and they ship fast.

[Noggie]

Originally Posted by Larry77

Too late now, but I would never buy something like this on Ebay. If you end up looking for different parts, check out RW Carbon, I just installed their rear diffuser and fitment was very close (only had to trim one of the tabs). Not sure why but it isn't letting me add a hyperlink, just search "RW Carbon". They actually will talk you through the install, they are in Cali, and they ship fast.

I'll give them a go.

Since this was bough on eBay and paid with PayPal, I could return the item and/ or file a claim against the seller to get my money back, might take some time though.

I had no intention on buying on eBay initially, but several people in a national M-group on facebook had good experience with this company, so I took a chance, in retrospect I shouldn't have.

[OneExtra]

Originally Posted by Dwaynos

I'm not 100% sure but I would say that would either need to be removed, which would probably cause comfort access issues or fault codes, or purchase a diffuser that is made to suit cars with the kick opener, either way the kick opener will not work and need to be coded out, even with the genuine m performance diffuser.

Coding it out might stop it from showing a fault if you removed it but you'd just have to try it.

I have the genuine M performance rear diffuser and nothing needs coding out, the kick opener just doesn't work anymore

[Dwaynos]

Originally Posted by OneExtra

I have the genuine M performance rear diffuser and nothing needs coding out, the kick opener just doesn't work anymore

Well you learn something every day, I read that on what I thought was a reliable source. I did wonder though when I fitted mine I didn't bother coding it out and had no problems.

[BeachM5nster]

if you bought oem there would be no issues

[Noggie]

Originally Posted by BeachM5nster

if you bought oem there would be no issues

OEM only has the center piece, and I think it is no longer available.

Still discussing with the seller, but if I don't get anywhere with them, Ill take it to eBay and/or PayPal.
Might end up loosing a bit, but not everything.

[Ickdeep]

I think that's just the risk of using eBay. I went with the RW Carbon one and it fits pretty good. I did have to take the bumper off and use screws to hold the diffuser in but it wasn't that bad. Did it myself I'm in like 2 hours.

[Noggie]

Well, I was skeptical with eBay, but several M-Owners said they had very good experience with then so I decided to give it a go.

Here is some pictures with explanation.

It was way off.

[Viper966]

take the bumper off, it takes 30 seconds, but you can then fit the diffuser easier and use screws through the tabs to close those gaps

[Noggie]

Originally Posted by Viper966

take the bumper off, it takes 30 seconds, but you can then fit the diffuser easier and use screws through the tabs to close those gaps

Still have the clash with the comfort access antenna.

I will send it back.

Buy a new bottom section from BMW and have it painted black instead.
Perfect fit and I can get the finish I want.

Thanks for the suggestion though

[Dwaynos]

Originally Posted by Noggie

Still have the clash with the comfort access antenna.

I will send it back.

Buy a new bottom section from BMW and have it painted black instead.
Perfect fit and I can get the finish I want.

Thanks for the suggestion though

Yes do that. Then get the carbon centre and your look will be complete

[tim99ws6]

Originally Posted by Viper966

take the bumper off, it takes 30 seconds, but you can then fit the diffuser easier and use screws through the tabs to close those gaps

Do tell how the rear bumper takes 30 seconds? Is there a removal write up on that?!

[Ickdeep]

Originally Posted by tim99ws6

Do tell how the rear bumper takes 30 seconds? Is there a removal write up on that?!

Its not exactly 30 seconds but it literally takes like 5 mins. 3 screws in the wheel well & one by the taillight on each side. Also don't forget to pull the sensors out of the bumper before fully taking it off.



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[valbmw]

Originally Posted by Noggie

Still have the clash with the comfort access antenna.

I will send it back.

Buy a new bottom section from BMW and have it painted black instead.
Perfect fit and I can get the finish I want.

Thanks for the suggestion though

Tough experience despite your good effort and patience.
I never believe in fake pieces, you know: "who buys it right, pays it once". The original Vorsteiner CF stuff costs high but fits precisely.

Your car is fantastic both from outside and inside, it just wants all perfect good luck!

[rickyf10]

Some sellers on eBay are not even aware of what they are actually selling. I suppose the diffuser you bought is for aftermarket m5 style bumper (for non-m f10 5 series), which is gonna fit perfectly.
Yes you may save a lot from buying eBay budget parts but gotta be very careful choosing the right ones. I bought my front carbon splitters for only 150$ lol, fitments ok, makes m5 a lot more aggressive