Can anyone tell me why an All4 S exhaust will not fit a FWD S Countryman. All the vendors say it won't fit but the only thing I see different is the FWD transmission does not have the bolts to mount the exhaust hanger bracket that the All4 does. Everything else is the same. Just trying to modify my exhaust to 2.5" and don't want to spend $1500 on one.

 

I know the FWD exhausts won't fit correctly around the AWD components. AWD should, technically fit, the FWD since there are no extras to around.

I would recommend going to an exhaust shop, picking up some good manga flow mufflers and have them put it all together. Probably be at least a 3rd of the cost of whatever $1500 system you're looking at. And sound better too.

Here is my custom system, 3" DP and 3" exhaust. 1 Magnaflow straight through muffler in the mid pipe and 1 straight through mufflers on the each exit pipe.



This was when I had an vibrant resonator in the mid pipe, I ended up replacing it with the straight thru Magnaflow muffler (video above) to cut down on some sound.

 

I believe that it will hit the transmission in the front is the fit issue. At least from what I can tell, the transmission layout is different between the AWD and 2WD as you can slightly see in the pictures you used. The AWD shifts over to the right to bolt to the transmission, avoiding the differential. But the 2WD has a slightly lower hanging transmission towards the exhaust side and I believe that is where you get minor interference. Honestly your best bet is to just get a custom exhaust made at a shop and save the money.