While I don't own the seat you have, I can confirm that mounting your shaker(s) to the back of your seat feels really great! I use it for engine and gear shift effects via Simvibe CM.
I've tried engine effects on my shakers underneath my seat and pedals, but much perfer the feeling on my back... Those effects travel through my rig too.
As long as you are committed to custom-mounting tactile immersion and you just can't race without it... Also, if you aren't looking to sell your seat for what its worth used in the future, then I would just do it!! IMO your seat would look very interestingly kool with shakers mounted on the back of it
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