If the brakes chatter when you brake, you might want to lower the brake settings a few notches.
Just in case you don't know this, you can filter your results. If I'm searching for McLaren GT4 Settings, configure the filter so it says "Show results as posts" and in the "Search in forums" category, I scroll down and highlight "GT4 Car Tuning & Settings". Click "Search Now" and that's how I came up with my links here.
Hope this helps,
Duck7892