I wanted to share a simple and relatively inexpensive DIY upgrade for those who didn’t want to purchase an exhaust system, yet are looking for an overall stealthier look or simply wanting to match the remaining blacked out trim. I did the same on my F85 which is a bit easier as it doesn't involve any cutting.
I bought the 3.75” slip-on tips from Burger Tuning for $100 with shipping.
They are currently on sale until they sell off the remaining inventory (see link below).. I do not think they will carry these afterwards so you may want to get yours ASAP if you’re interested in doing this mod. They don’t have black in stock, only chrome or burned blue. You can get either one and powdercoat them black. I had mine done in gloss black along with stock tips for ($68). This brought grand total for this mod under $170.
The tricky part of this install is to extend the existing slot to a total distance of 2-3/8" which will ensure tips do not stick out too far from edge of the bumper. It will also ensure that inner pipe is wedged into double edge oversized tip you are installing for a firm fit. I cut the slot on mine using a grinder wheel. I marked my lines with a marker, drilled at the end point and made the cuts using grinder wheel. Once this is done i bent the tabs (as per instructions on the pics) to ensure they go on smoothly without massive pressure needed. Once i test fitted each tip i took them to powdercoater.
Keep in mind this is biggest tip you can run on F90 as the distance between each tip is merely 3mm give or take. I personally love the look and how it fills up bumper tip opening. See pics to judge for yourself.
BMS can thank me later for helping them move their close-out inventory tips!
http://www.burgertuning.com/exhaust_...M3_M4_BMW.html
