Why no SW and AW pre-made motor brackets?

I'm starting to think about building my first brass chassis.
I've been won over by the SW configuration during the past year (whenever the width of the car/chassis permits it) and I've been fascinated by the AW set-ups, although, to date, I haven't had much luck with them on the track. Since SW is my current favorite motor configuration, I started looking around for a pre-made SW motor bracket that accepts the rear axle bushings/bearings and the motor (like what's already available for the IL configuration). I can't find any and I wondered why that is? I would think that there would, at least, an S-can (FC-130) SW version. Am I missing these pieces or do they not exist? And if they don't, why is that? Thanks.
Allan
I've been won over by the SW configuration during the past year (whenever the width of the car/chassis permits it) and I've been fascinated by the AW set-ups, although, to date, I haven't had much luck with them on the track. Since SW is my current favorite motor configuration, I started looking around for a pre-made SW motor bracket that accepts the rear axle bushings/bearings and the motor (like what's already available for the IL configuration). I can't find any and I wondered why that is? I would think that there would, at least, an S-can (FC-130) SW version. Am I missing these pieces or do they not exist? And if they don't, why is that? Thanks.
Allan