I've owned 2nd gens for about 20 years now. I can practically build one in my sleep. However, there is one thing I never got around to figuring out and I'm sure that someone knows it. I've had a few S4's and now have an S5. I absolutely hate the automatic seatbelt. Does the S5 chassis still have the provision in place to retrofit the older S4 seatbelts? My thinking is that it isn't there but I'm secretly hoping it is. Even if it does it still leaves the issue of needing the interior panel from an S4 and I have a black interior which the S4 did not. Anyways, can S4 seatbelts work in an S5?

 

Yes, it does.
I've retrofitted both my S5s with manual belts.

 

Hallelujah! Now to find some belts and interior panels and then make them black. Thanks.

 

10th AE S4s have black interiors.

I took the easy way out and put a roll bar and harnesses in mine

also, if you take the mouse tracks out of an S5, the A pillar trim no longer has anything to snap into... which stinks.

 

There is one good thing about the mousetrap belts. If they ever fail Mazda has to fix them for free.

 

could get canadian s5 trim eh

 

i actually know someone up the street parting an s5 with blk interior. but shipping those panels over the border would be costly

 

I have an S5. I'd need black S4 parts.

 

I think he's implying that canadian S5s had normal seatbelts.

 

the S5 has auto seat belts in the US ONLY, in the rest of the world it has normal belts.

there is a fairly long list of bits needed.

the seat belt assemblies, which are NLA.
the A pillar trims, which are available
the headliner (the S5 is shorter)

the B pillar trims, rear bin holder (the fiber thing), and rear carpet are different too, although these are kind of optional (the trims make room for the auto seat belt motors)

the center console is different too, although you don't need to do anything

also the carpet is different, the S5 has an extra cut for the lap belt retractor.

 

so what would he need to swap in seatbelts from a cdm s5?

 

I didn't know that only we got auto belts. Still learning about these cars after all these years.

 

S4 trim does not fit a S5.
The b-pillar trim can remain just as it is, all you have to do is cut a hole in the upper panel to access the chassis shoulder mount.

The S5 headliner is cut higher to accommodate the mousetracks, the S4 a-pillar trim is too narrow to cover the gap, so you must use the S5 trim anyway.

 

I'll make it all fit. Re-doing a headliner is easy.

 

If it helps, I have the black headliner from my Canadian S5. Unfortunately the rest of the interior was parted out a couple years ago, along with the manual seat belts. Only thing that could be a problem is that mine was a hard top so the headliner is solid with no opening for a sunroof.