If they are like the ones you can get for the 350Z they are very heavy steel with some beefy springs to counterweight the door.Apart from the fact they will slow you down, make the car roll more on corners, and are over priced I also think they look awful, look difficult to use, the doors look vulnerable to gusts of wind, and the door frame looks easy to damage if you get the action wrong.So you might have guessed they aren't on my shopping list