New exhaust, diffuser, and paint correction

[Sleepybear]

Just picked up my 2012 650i M-Sport Coupe 6-Speed after having a little work done on it. I loved the look of the carbon fiber rear diffusers, and wanted a little louder of an exhaust. Big thanks to DerBosewicht and skilz4u2nv who helped point me in the right direction in terms of getting it done right.

I started by purchasing the M6 Lower Cover so I would be able to fit the CF diffuser, along with CF exhaust tips and the 3-piece diffuser from eBay. I took the 6 to a local exhaust shop who cut out the exhaust and welded in stainless steel pipes to get the tips to fit properly. The guy at the exhaust shop was very helpful, and they basically were able to get the lower cover on to ensure the fitment was good. His brother happens to be a BMW enthusiast who works at a paint/repair shop, so the next step was bringing everything to his shop.

I had the lower cover painted, 2 tow-hook covers (which were only primed) painted, touch up paint on the front bumper/hood/grill, and then the CF diffuser, trunk spoiler, and mirror caps all sanded and clear coated (looks so much better/deeper, and won't yellow in the sun). I also had them wet sand the hood, roof, and trunk lid to try to get rid of the etching. They also fixed a few dents on the passenger side before installing the rear diffuser. The fitment on the diffuser is not perfect, but it was a cheapo from eBay so I was expecting that to be the case.

I had spent an absurd amount of time detailing the car when I first purchased it, but given it had spent quite a bit of time outside in FL with the previous owner, the paint had deep etching/water spots that I simply could not get through, and wasn't willing to try wet sanding myself. Even after wet sand/buff/polish some defects are still present, but it was not worth the cost to do a full respray on all the affected areas at this time.

The attached pics more or less show the progress on the paint as I was doing my detail (and the etching I couldn't get through), the lower cover being installed, and then how it looks today. The last 2 pics are out of order, but show what the front looked like prior to the touch-up.

There is still some work to be done, but love how it looks and sounds now! I'll try to upload a cold-start video later.

[Opie55]

So it's a manual? Pretty rare. I got over my fear of wet sanding and do it all myself now. But letting experienced detailers handle it is probably nice. How do you get in it with it parked that close to the SUV?

[J_ONeill]

I've been eyeing this project for a while. Did you just cut the square tips off like Skilz did or did you have to cut further back?

Also do you have a link for the tips? From what I've read the outlet size is different for the 650 vs m6 mufflers

[Sleepybear]

Originally Posted by Opie55

So it's a manual? Pretty rare. I got over my fear of wet sanding and do it all myself now. But letting experienced detailers handle it is probably nice. How do you get in it with it parked that close to the SUV?

It is a manual - Spent at least two years searching the country for the right one that wasn't a convertible or super high mileage. I'm sure I'll get into wet sanding paint work at some point, but with this car being my baby was worth making sure it got done right and saving that learning experience for something else.

And I get in very carefully! I always back in and leave enough room for the driver, any passengers just get in outside the garage.

[Sleepybear]

Originally Posted by J_ONeill

I've been eyeing this project for a while. Did you just cut the square tips off like Skilz did or did you have to cut further back?

Also do you have a link for the tips? From what I've read the outlet size is different for the 650 vs m6 mufflers

I wanted to try that at first, but the shops welding guy was very particular and said that there was no way to make it work with the little pipe that would be left after cutting off the tip and the angles they were at (at least with my tips). The attached image is how far back they went, which is nice because it should be possible to undo it if needed at some point.

In the end I'm glad I went with the full muffler delete. It was really loud/droney on the drive home, but seems to have found a balance now and sounds great without too much drone.

I'm not sure if I'm allowed to link directly to ebay - but if you search "2PCS Glossy Black Carbon Fiber Exhaust Tip For M Performance BMW Universal Pipes" that is what I went with. 2.5" inlet, 3.5" outlet. I heard that there is a difference in the mufflers as well, and I think the angle of the pipes to the tips on the 650 play a part in that (though again, it may be possible with a different set of tips).

[Sleepybear]

Here is a vid of the cold start: https://www.youtube.com/shorts/9MWtSMiuQ5Y

[antmay]

Hi Sleepybear,
Car looks great. I have 2 questions...

- I must have the M6 Lower Cover in order to install the rear diffuser?
-Will the stock exhaust ( rectangle tip ) works with your new rear diffuser?

Thanks

[J_ONeill]

Originally Posted by antmay

Hi Sleepybear,
Car looks great. I have 2 questions...

- I must have the M6 Lower Cover in order to install the rear diffuser?
-Will the stock exhaust ( rectangle tip ) works with your new rear diffuser?

Thanks

nico_x_650 on IG has same diffuser setup with the stock exhaust if you want to look

[antmay]

Originally Posted by J_ONeill

nico_x_650 on IG has same diffuser setup with the stock exhaust if you want to look

Thanks for the information.

[Sleepybear]

Originally Posted by antmay

Hi Sleepybear,
Car looks great. I have 2 questions...

- I must have the M6 Lower Cover in order to install the rear diffuser?
-Will the stock exhaust ( rectangle tip ) works with your new rear diffuser?

Thanks

From everything I've found, yes, you do need the M6 Lower Cover in order for the rear diffuser to fit/work. I had ordered a different style diffuser before this one, but it did not fit without the M6 Lower Cover.

The stock exhaust won't work with the new diffuser, it just wouldn't fit over it.