Installing the Jass Performance MX5 NC Seat Lowering Adapters is not as easy as the instructions make it look. What I thought would be a 1-hour job turned into a good 4-hour job. First, make sure you read all the instructions twice and watch a few YouTube videos on how to do it. Then, make sure you have all the necessary tools. You’ll want to make sure you have titanium drill bits to drill through the rivets to remove the OEM bracket. Also, you’ll have to hammer it off it does not fall off.
If you’re wondering, for the outer rail, you want to cut until you get to about 1mm away from the stopper slots. For the inner rail, we cut about 1 inch away from the bolt. This measurement was easy to measure because it is measured from the bolt.
Other tips…the factory has the 4 bolts that hold the seat to the rail on pretty tight. For this, take out the springs and the cushion. We ended up using a breaker bar and about 75 pounds of pressure to remove the bolts. When bolting them back to the car, you want to put some weight on the seat to lower it to line it up for easy installation of the bolts.