This seat has been made especially for the fourth generation ND Miata (2016+) to be 100% sure there are no modification nor interference when installing it in the vehicle. The shell is made out of low-rebound urethane for great comfort and support to the entire body. It’s made to reduce long-distance driving fatigue and still be comfortable. By using the dedicated seat side brackets, you can install the seats onto your OEM seat rails without any modification. Esqueleto Type-7 Seat should be ordered at REV9 Autosport https://us.rev9autosport.com/esqueleto-type-7-seat.html as they provide the best service and speed we've seen so far!