Epic has uploaded a nice pack, which includes 75 material instances from the 2016 GDC McLaren 570S demo. You are free to use them in your projects.
The Automotive Material Pack is a collection of high quality automotive-themed PBR Materials and Textures which have been setup for use in Unreal Engine 4. The pack features 21 Master Materials and 75 Material Instances sourced from Epic’s 2016 GDC McLaren 570S demo.
The categories of Materials included are:
You can check out more info about this pack in Unreal Engine Marketplace.