yea the battery box floor had to be cut and modified then we rewelded,seam sealed and some bedliner coating on the underside , the battery sits alil bit higher so the trunk trim underside the ribs had to be burnt off to make for the diffrence of where the batt. sits now...i love the sound not too loud during reg. driving but a good tone when you get on it...I wanted to thank socal,west and everyone elses feedback in this thread that made it a lil bit easier to put this set up together....

 

:d

 

Here's mine, though not quads.

 

Here's mine that I did a couple of years ago. Part numbers are in the video link that's in my signature. It's not a great video, but every time I try to take a new one with my phone, the tone of the exhaust blows out the phone mic and sounds like crap.

Oh yeah, I just recently removed the rear bumper and fixed that diffuser. Still doesn't fit all that great, but whatever.

 

Lookin good guys. Looking at this thread makes me miss the 545i.

 

The big issue with quads is the Joe Sixpack that decides to do it himself. If you are worried about a loss in hp, then research and invest in good quality quad exhaust system from reputable company. They should have test data to share then make your decision. Most of these companies have invested a lot of money in R&D. If cost is your concern, then there are some reasonable ways to get the quad look, but in most of these cases you drop a little hp, not much but you might notice it the first time you drive, after that I doubt it. In some cases you will not drop any might even gain a tiny bit but you then have that nasty droning issue. Also keep in mind that naturally turbo aspirated engines exhaust do not behave in the same fashion. A lot of these threads get very dirty because of being mixed from multiple postings.

 

I was alil worried about hp loss but my car feels just as strong if not alil bit more responsive after the new exhaust setup.....

 

My original setup the car felt more responsive and no loss. then I added the turbo mufflers to kill some drone, and then I could feel a little loss for the first few hours. I guess I am used to it now.

 

If you do not mind can you tell me how much it cost you? Did you bring your own parts or shop had them?
Thanks

 

While waiting on my M5 rear bumper to come in, I have been looking at exhaust tips in the meantime.
What do y'all think about blue exhaust tips? Is it to "ricey" or "frowned upon"? I think it looks great... just wanted to know everyone's opinion before I pull the trigger

Universal Polished Stainless Steel Dual Exhaust Tip 2 5" Inlet 3 5" Outlets Pair | eBay