Storyline concept is basically explained in the beginning of the trailer but if you would still be confused:

Chen Kai Xiumin and Baekhyun are secret agents who have to infiltrate a race organized by BLACKPINK, a criminal gang who steals jewelry and then resells it on the black market. All the rest you see of iKON and EXO are potential buyers. Who will buy the diamond? That's something the secret agents will have to figure out.

Songs: 1) F1 theme intro (2018)
––––––––––––––––––––––––––––––
2) Dystopia by Luke Hall   / c_luke_hall​  
Creative Commons — Attribution-ShareAlike 3.0 Unported — CC BY-SA 3.0
Music promoted -    • Video  ​
––––––––––––––––––––––––––––––
3) 16 Shots - Stefflon Don

I don't own any of the video material of the idols, I did make the HUD in the beginning myself.