I was trying to get my hand on a set of Magnaflow #15227 for my 3xx but those darn things are BO since january and still not sure if they will produce them anytime soon so ...the hell with it, i ordered a kit for a RC350 with double tips !!
Normally it should be almost the same fit minus probably the anchors in the back since the bumper is not the same ...none the less, i tried a virtual fit and it should be fitting quite nicely i think :P
I photoshop two pictures and matched as much as possible the bolts, scuff plate ect ect ...results is good ..... Can't wait to start *****ing at the install lolll

But the sound should be interesting with my Apexi Midpipe

 

The diffuser will be the only thing you'll need to change to a 2017-2020 one

 

Yep i just received my new one yesterday but ..... this plastic junk is all out of shape and not fitting on the bumper at all !!! I will have to leave it in the Sahara desert for a week to make it soft enough to fit and maaaannnn ...Magicdrift or whatever company that makes those ... what a ****ty product quality they make !!! Full of bad forming spots and look so fragile and cheap !!!!
Not sure if i should recommend this part to anyone to install but got no choice as it is in and paid for :P ...this is probably my karma for trying to find quick and cheaper way of fixing things ....worst part is that i professionally build airplane for a living so i'm kinda out of my 0.0001" tolerance fit :P lmao

 

So short story, RC350 fits perfectly but a bit close to center tow hook ... Apexi Mid-Pipe and Magnaflow exhaust .....SOUND IS AMAZING !!!!
I don't like my diffuser as it is the cheapest and mainly fastest delivery one i could find but for now it will do

 

So basically all rc3xx axleback will fit 2017+ is3xx (quad tips)?

 

Something about that sexy exhaust completely changes the back end on these cars!

 

Should fit but like i wrote mine is a 2016 so
**NOTE** i have a little drone from the open mid and mufflers combo but with louder good music ..... who cares as the sound with AEM filter and all is amazing Gain a bit on power HP but would need to get that tuning done and in Quebec .... good luck to find one that can Dyno Lexus and to spend $569us on RR racing kit with out knowing if it will only bring the RPM to 7200 and adjust it to the 350 specs ++ seems to be a gamble ?~?~?

 

Sound Clip?

 

I'm trying to do the same thing with my 2014 3is250 f-sport. My buddy is giving me the exhaust for free, so I gotta take advantage. DId you have to do any custom work to the actual exhaust? Or was the custom work all with the diffuser? Are there any other diffusers you think would work?

Thanks for posting this!

 

The exhaust is bolt-on. Only thing you'll need is a 2017+ diffuser as the "holes" are bigger to fit quad tips. You could even try with the 2014 diffuser, I was able to squeeze some Magnaflow double 3in tips on my 2015 back in the days.