Not required mate, save your money!
Most people are running the car with 60g in the chassis spine and leaving it at that!
I ran my car heavy all this year and to be honest wish I had of run it lighter as when I tested it light it was EVEN BETTER .... and I didn't think that was possible
If you are adding wieght to try and get more rear end grip or correct some handling issue please post up and we will go through the set-up and sort it for you, car is brilliant straight from the box but a bit of tuning and wow.