[techn0ir]

I’m planning to pick up a few bits of carbon fiber from rw carbon pretty soon: Front lip, trunk spoiler, and rear diffuser. These are for my Estoril blue 335i which have CF mirror caps from the factory. I feel pretty comfortable installing the spoiler and lip, but a bit hesitant to install the diffuser myself since it requires removing the bumper cover (per instructions on the website), which I’ve never done on any car.

Any ideas how much it should cost, ballpark, to have the diffuser installed by a pro/body shop? Or should I really just try to DIY it myself (no one around to help)?

[bmwchue]

Diffuser is as easy as the front lip. Lots of DIY on youtube

[ooshnoo]

You can install it yourself in less than 10 minutes

[EDWYER]

I would think around 250-350 for the install cost.

[Kailec]

I would honestly suggest you do the diffuser yourself. I haven't don't it yet since I'm waiting to buy the exhaust, but it looks dead simple. Unscrew old one, screw in new one..

[lonecitizenfour]

Unless you're getting some aftermarket diffuser with different-than-OEM mounts (a CF Diffuser I got had different mounting hardware) you can take it off / put it on yourself.

It's couple screws with 2 different head sizes pop on / off.

[M2Rush]

Others that have said it's easy to install diffuser, do keep in mind that he did say Carbon Fiber which does not flex like the poly/matt black version. Therefore you'd have to remove the bumper to get it on properly, otherwise you risk cracking the expensive diffuser. I guess it is possible to have it installed without removing the bumper but there's a big chance that you'll end up cracking it. Not trying to undermind anybody, just my honest opinion.

[sewhelan9]

I installed a RW Carbon rear diffuser (poly version, not carbon fiber) last week by removing the rear bumper cover of my F36 and it took less than 30 min. and was very simple and straightforward. Keis Motorsport has a great video covering the process and the basic tools needed.

[techn0ir]

Thanks everyone, appreciate the feedback. I’m going to go ahead and give it a shot DIY.

[IK6SPEED]

Originally Posted by ooshnoo

You can install it yourself in less than 10 minutes

I have to assume you are correct.

An Independent was doing brakes and rotors for me (did not purchase from them) and threw it on for me at no charge.

[ooshnoo]

Originally Posted by IK6SPEED

I have to assume you are correct.

An Independent was doing brakes and rotors for me (did not purchase from them) and threw it on for me at no charge.

I'm speaking from experience.

[IK6SPEED]

Originally Posted by ooshnoo

I'm speaking from experience.

That's my point. If it took more than a few minutes I am sure I would have been charged.

[B58 parts]

If you have to remove the bumper, it is pretty easy, just be liberal with the masking tape, and be really careful with the PDC sensors if you have them.

They are held on with I guess some very small amount of adhesive. When reinstalling the bumper the whole thing slipped on me and one of the sensors snapped off. I had to krazy glue it back on. W/e

[johnung]

I just installed a rear diffuser from proautomotion (not carbon fiber) on my 2015 335i Xdrive. Check out two videos from Kies Motorsports. One install with removing bumper and the other without removing it. I did not remove mine.
Here are the steps along with the tricks that I learned.
1) Remove the stock diffuser which is a grey panel.
a) Underneath remove two 8mm screws on each side.
b) Underneath remove three T-15 screws in the center.
c) It can be an easier install if you remove the left and right deflectors that are just above the panel. There are three different types of fasteners molded into the back of the plastic reflectors on the rear M Sport bumper. Start at the end of each reflector closest to the center of the car. Reach behind with your hand and push out connector at the end of the reflector. Then push out the connector at the middle of the reflector. It's oriented so you push out and down, but it pretty much pops out with a little pressure. The last connector on the outside of the reflector is a slide in. So once you have the other two out just slide the reflector towards the center of the car and it will come right out in your hand. Once you take one out and see how the connectors are oriented on the back you will be able to remove and install them in seconds.
d) Now the stock diffuser panel is just being held in by 10 built-in connectors that attach it to the plastic components to the side and above it. The trick is to start all the way at one end and pull the bottom end out to release the vertical connector holding in the side. Then progressively pull a little at a time releasing each of the 8 connectors at the top working your way across to the other side until you pop the last vertical connector at the far side.
2) You have great access now to clean and polish chrome exhaust tips if you have them. I got great results by using a sponge with hot water and dish soap. Then used a tooth brush to scrub them more. Then used the tooth brush with 409. If you still feel grit on the surface you can clay them. Or use 2500-3000 grit paper and wet sand with the hot soapy water. Toughest part was the black grime on the inside of the lip. Did all of the above then wet sanded inside lip with suds and 409 as lubricant first with 1500 grit, then 2000 and finished with 2500. Dried and applied and buffed three coats of Mother's chrome polish. Now they look brand new. Monster difference.
3) Install the new diffuser in reverse order. Check out the two Kies Motorsports videos and you'll have no problem doing it yourself.
Hope this detail helps. Just installed mine this morning and couldn't be happier with the result.

[Kailec]

I think everyone's experience will be a little different. My side clips came out easy. It was the 8 on top that was more difficult, some were more stuck in than others. What helped me was putting my hand behind the diffuser and pushing out one with my finger (for me it was the one closest to the left reflector from the center), then I could reach my hand in more from the front and pull out the rest. Certainly wasn't hard by any means, and you save a lot of money by doing it yourself.

[sukhparm.7]

Maybe this Video will help. Friend of mine made this

[Bryan_KiesMotorsports]

Originally Posted by sewhelan9

I installed a RW Carbon rear diffuser (poly version, not carbon fiber) last week by removing the rear bumper cover of my F36 and it took less than 30 min. and was very simple and straightforward. Keis Motorsport has a great video covering the process and the basic tools needed.

Thanks for the shout out

Bryan

[Bryan_KiesMotorsports]

Originally Posted by johnung

I just installed a rear diffuser from proautomotion (not carbon fiber) on my 2015 335i Xdrive. Check out two videos from Kies Motorsports. One install with removing bumper and the other without removing it. I did not remove mine.
Here are the steps along with the tricks that I learned.
1) Remove the stock diffuser which is a grey panel.
a) Underneath remove two 8mm screws on each side.
b) Underneath remove three T-15 screws in the center.
c) It can be an easier install if you remove the left and right deflectors that are just above the panel. There are three different types of fasteners molded into the back of the plastic reflectors on the rear M Sport bumper. Start at the end of each reflector closest to the center of the car. Reach behind with your hand and push out connector at the end of the reflector. Then push out the connector at the middle of the reflector. It's oriented so you push out and down, but it pretty much pops out with a little pressure. The last connector on the outside of the reflector is a slide in. So once you have the other two out just slide the reflector towards the center of the car and it will come right out in your hand. Once you take one out and see how the connectors are oriented on the back you will be able to remove and install them in seconds.
d) Now the stock diffuser panel is just being held in by 10 built-in connectors that attach it to the plastic components to the side and above it. The trick is to start all the way at one end and pull the bottom end out to release the vertical connector holding in the side. Then progressively pull a little at a time releasing each of the 8 connectors at the top working your way across to the other side until you pop the last vertical connector at the far side.
2) You have great access now to clean and polish chrome exhaust tips if you have them. I got great results by using a sponge with hot water and dish soap. Then used a tooth brush to scrub them more. Then used the tooth brush with 409. If you still feel grit on the surface you can clay them. Or use 2500-3000 grit paper and wet sand with the hot soapy water. Toughest part was the black grime on the inside of the lip. Did all of the above then wet sanded inside lip with suds and 409 as lubricant first with 1500 grit, then 2000 and finished with 2500. Dried and applied and buffed three coats of Mother's chrome polish. Now they look brand new. Monster difference.
3) Install the new diffuser in reverse order. Check out the two Kies Motorsports videos and you'll have no problem doing it yourself.
Hope this detail helps. Just installed mine this morning and couldn't be happier with the result.

Glad the videos helped, thanks for checking us out

Bryan

[gfa3]

Just wanted to chime in because it seems no one mentioned this but there is a pretty big difference between installing a rear diffuser on a PRE-LCI F30 vs. LCI F30.

With the LCI they added lots of heat shielding. I've taken a look at mine a bunch and I'm pretty sure you have to remove the bumper as done in Bryan from Kies Motorsports video.

Still waiting for mine to come in!