[Sylverlee]

Does anyone have experience with these "M5 rear diffusers" on eBay? I wonder if the exhaust cut outs are brought in the center similar to the OEM M5?

https://www.ebay.com/itm/Rear-Diffus...Cclp%3A2334524

[lsturbointeg]

it's a hit or miss bud when it comes to Ebay. mine was fine but it took some finesse to get the tabs to fit and i had to use screws to keep the tabs from pulling out. keep in mind there's 2 versions...M5 and MSPORT. the M5 the exhaust openings on the diffuser is going to be more inward like mine. the MSPORT openings will be like that of a 550. when i had the muffler shop install my Meister's they had to line it up quite a bit

[spielnicht]

Yes, it's easily to tell whether they're M5 spec or not. If you look at that second picture focused on the edge, you'll notice it's pretty beefy. That tells you it's an M5 spec and thus made to accommodate more inward muffler tips (or an M5 muffler).

If you look at this diffuser for example, you'll notice that the sides are much slimmer, that tells you it's made for the 550i and more outward muffler tips (a stock or aftermarket 550i muffler).

https://www.ebay.com/itm/For-BMW-5-S...AAAOSwsmdd7a7w


I believe they also make ones for the 535i to accommodate single muffler tips and those actually have the same beefy sides as the M5 spec.

https://www.ebay.com/itm/Rear-Diffus...QAAOSwZQpf9sx8

[Sylverlee]

Thanks guys!

This is my current setup. It actually looks more beefy than the Msport setup, you think I might already be setup for M5 positioning?

[spielnicht]

I'd say based on the fact that your inner muffler tip is sitting right under the tow hook cover, definitely an M5 spect setup.

You can see in mine that my inner muffler tip alignment is off from the tow hook cover.

[Sylverlee]

Originally Posted by spielnicht

I'd say based on the fact that your inner muffler tip is sitting right under the tow hook cover, definitely an M5 spect setup.

You can see in mine that my inner muffler tip alignment is off from the tow hook cover.

Astute observation! Appreciate that 🙏

[Sylverlee]

Actually looking at it more closely, I just realized mine is off the tow hook, like yours. I must have the normal 535/550 setup. If you don't mind me asking, where did you get your diffuser? Looks really good.

[Sonymonytony]

Nice looking bumper!!

[spielnicht]

Ah yeah, from that angle definitely looks like mine then. I was a bit suspicious because of the slanted opening, a common design to accommodate 550i stock trapezoid tips.

This is the one I have. I got 3 total (all different vendors) before I settled on this one because I definitely was after near fitment perfection. It's more expensive than others, but it's made in Taiwan (vs China) and very well worth it (for me at least). To my delight, came in a wooden crate vs just a cardboard box The fitment is 99.9% perfect. I ended up painting over the CF because I wanted the M5 look. The center is plasti-diped because I haven't mastered 2-tone paint and wanted a matte look to give it depth.

https://www.ebay.com/itm/Carbon-Fibe...72.m2749.l2649

Originally Posted by Sylverlee

Actually looking at it more closely, I just realized mine is off the tow hook, like yours. I must have the normal 535/550 setup. If you don't mind me asking, where did you get your diffuser? Looks really good.

[Sylverlee]

Originally Posted by spielnicht

Ah yeah, from that angle definitely looks like mine then. I was a bit suspicious because of the slanted opening, a common design to accommodate 550i stock trapezoid tips.

This is the one I have. I got 3 total (all different vendors) before I settled on this one because I definitely was after near fitment perfection. It's more expensive than others, but it's made in Taiwan (vs China) and very well worth it (for me at least). To my delight, came in a wooden crate vs just a cardboard box The fitment is 99.9% perfect. I ended up painting over the CF because I wanted the M5 look. The center is plasti-diped because I haven't mastered 2-tone paint and wanted a matte look to give it depth.

https://www.ebay.com/itm/Carbon-Fibe...72.m2749.l2649

haha you know what - I think I have the exact same diffuser. Mine is still CF though.. Maybe i'll paint it like yours, def gives it some depth vs. being one color. I might try doing it myself using https://www.automotivetouchup.com/ I've seen videos, the 2k Clearcoat is the secret I think.

[BimmerRalph]

I recently ordered that diffuser for my f10, I will most likely spray it glossy black im not a fan of that fake carbon.. Ill let you know how fitment is!

[Sylverlee]

Originally Posted by BimmerRalph

I recently ordered that diffuser for my f10, I will most likely spray it glossy black im not a fan of that fake carbon.. Ill let you know how fitment is!

I already have it on. Fitment was good, said my installer. Bumper needs to come off. I’ll prob spray mine too.. neutral on the carbon.

[spielnicht]

Sp*****x 2K Glamour Coat is definitely the secret in the sauce. Also, avoid the mistake I initially made and make sure to use white primer (if you decide to go white).

Originally Posted by Sylverlee

haha you know what - I think I have the exact same diffuser. Mine is still CF though.. Maybe i'll paint it like yours, def gives it some depth vs. being one color. I might try doing it myself using https://www.automotivetouchup.com/ I've seen videos, the 2k Clearcoat is the secret I think.

[lsturbointeg]

here's my setup

[Sylverlee]

Originally Posted by lsturbointeg

here's my setup

👌aggressive

[Sylverlee]

Originally Posted by spielnicht

Sp*****x 2K Glamour Coat is definitely the secret in the sauce. Also, avoid the mistake I initially made and make sure to use white primer (if you decide to go white).

Did you just use one 12oz of paint and one 12oz of clear?

[spielnicht]

The #300 base coat (also purchased from automotivetouchup.com) I sprayed with a paint gun, but 12oz should be more than enough for 3 coats. The 2K I used just one 12oz bottle as well and I believe I got 4 coats out of it. Wanted that additional coat to protect from the heat coming out of the muffler tips. If you want more detail, I can write up exactly the procedure I followed.

Originally Posted by Sylverlee

Did you just use one 12oz of paint and one 12oz of clear?

[Sylverlee]

Originally Posted by spielnicht

The #300 base coat (also purchased from automotivetouchup.com) I sprayed with a paint gun, but 12oz should be more than enough for 3 coats. The 2K I used just one 12oz bottle as well and I believe I got 4 coats out of it. Wanted that additional coat to protect from the heat coming out of the muffler tips. If you want more detail, I can write up exactly the procedure I followed.

I was going to just follow their videos. But if you have any recommended changes? Usually just sand, primer, sand, base, and clear?

[spielnicht]

Yeah those videos helped me a lot, especially when it comes to applying the paint. Here is the general process I used for the diffuser and front lip, if it helps:

• Wet sand the diffuser with #400 just enough to remove the shine from the clear coat
• Wash, dry and wipe with surface prep wipes
• GLIDE tack cloth across surface to remove any dust (don't press hard or wax will transfer to surface)
• Spray 2-3 coats of primer
• Wet sand with #500
• Wash, dry and wipe with surface prep wipes
• GLIDE tack cloth across surface to remove any dust
• Spray 3 coats of base coat
• Wait 30-60 mins to and then spray 3-4 coats of 2K
• Let it fully cure for 48+ hrs

A lot of conflicting opinions on whether to wait 30 mins or 1 week between base coat and 2K clear coat. I went with the former and it came out great. You will end up with some orange peal, but luckily being white you can't notice it and I didn't even bother wet sanding. The orange peal is NO WHERE as close to what you'd get with regular acrylic clear coat.

Best advice I got from all of the videos and articles I read is spending as much time as possible on prepping is the key to getting a good results. I literally spent 4-5 days (in between work and family) prepping the diffuser before painting it.

Good luck!

Originally Posted by Sylverlee

I was going to just follow their videos. But if you have any recommended changes? Usually just sand, primer, sand, base, and clear?

[Sylverlee]

Originally Posted by spielnicht

Yeah those videos helped me a lot, especially when it comes to applying the paint. Here is the general process I used for the diffuser and front lip, if it helps:

• Wet sand the diffuser with #400 just enough to remove the shine from the clear coat
• Wash, dry and wipe with surface prep wipes
• GLIDE tack cloth across surface to remove any dust (don't press hard or wax will transfer to surface)
• Spray 2-3 coats of primer
• Wet sand with #500
• Wash, dry and wipe with surface prep wipes
• GLIDE tack cloth across surface to remove any dust
• Spray 3 coats of base coat
• Wait 30-60 mins to and then spray 3-4 coats of 2K
• Let it fully cure for 48+ hrs

A lot of conflicting opinions on whether to wait 30 mins or 1 week between base coat and 2K clear coat. I went with the former and it came out great. You will end up with some orange peal, but luckily being white you can't notice it and I didn't even bother wet sanding. The orange peal is NO WHERE as close to what you'd get with regular acrylic clear coat.

Best advice I got from all of the videos and articles I read is spending as much time as possible on prepping is the key to getting a good results. I literally spent 4-5 days (in between work and family) prepping the diffuser before painting it.

Good luck!

🙏 thank you, much appreciated.

[RJV3]

If you have comfort access, we're you able to retain the kick to open trunk feature?

[Sylverlee]

Originally Posted by BimmerRalph

I recently ordered that diffuser for my f10, I will most likely spray it glossy black im not a fan of that fake carbon.. Ill let you know how fitment is!

Ralph - did you end up buying the diffuser from the seller up top? Did it fit without moving the exhaust tips?

https://www.ebay.com/itm/Rear-Diffus...Cclp%3A2334524