Even though this mod is purely for handling purposes, the visual results are the most noticeable, so I thought 'inside and out' was most appropriate. My IS is a NASA time attack car so handling is the most important attribute for my car. With quick switchbacks and chicanes, the car leans a lot more than it should, many fellow racers I talked to said it was due to the sunroof, so I broke out my wallet and the project began.
The process began like this:
Get a spot weld cutter bit about 3/8” like a rotabroach and drill away.
Once all the welds are gone pop the panel off and put on the new panel & reinforcements.
Once this roof skin material is gone, clean up all reinforcements. Use the body sealer on the reinforcements then place roof skin onto the car.
Spot-weld the new roof into place or if you do not have a spot welder then you can mig weld it then grind the weld spots down (which is what I did)
Then make sure the molding gutters are smooth so the moldings fit into the gutters nice and flat………line up and fitment is key.
Then use the bodysealer on the connected joints and you are ready for the paint shop.
Then put back all the interior pieces and tada, the solid panel swap is complete.
The handling difference is night and day, the car can snap into any line I want to put it without the excessive roll from the extra weight on the highest point of the vehicle.
Special thanks goes out to gcomb and superchargedis200 for their help.
The process began like this:
Get a spot weld cutter bit about 3/8” like a rotabroach and drill away.

Once all the welds are gone pop the panel off and put on the new panel & reinforcements.

Once this roof skin material is gone, clean up all reinforcements. Use the body sealer on the reinforcements then place roof skin onto the car.

Spot-weld the new roof into place or if you do not have a spot welder then you can mig weld it then grind the weld spots down (which is what I did)

Then make sure the molding gutters are smooth so the moldings fit into the gutters nice and flat………line up and fitment is key.

Then use the bodysealer on the connected joints and you are ready for the paint shop.

Then put back all the interior pieces and tada, the solid panel swap is complete.


The handling difference is night and day, the car can snap into any line I want to put it without the excessive roll from the extra weight on the highest point of the vehicle.
Special thanks goes out to gcomb and superchargedis200 for their help.