how can I raise the miata mx5 drivers seat

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I recently did this by removing the two rear seat bolts and shimming up the rear of the seat only with washers and longer bolts. I brought the original bolts with me and purchased longer bolts with the added length that I wanted to raise my seat , 1 1/2 inches . This made a large difference in ht. by raising the rear of the seat which is tipped rearward at an angle. Don't buy longer than you need because they will puncture the floor and cause problems later.