To unlock the “It’s Showtime” Achievement / Trophy in Burnout Paradise, you need to complete the Showtime Road Rule on East Crawford Road with more than 1.5 million points. This road is located north in the Palm Bay Heights. The East Crawford Road covers a wide area and gives you more than enough space to set a new Showtime Road Rule. Also, you don’t need to finish your Showtime on East Crawford Road, you only need to start it here.
Before you start, make sure you set your tracker to “Best offline time” by pressing up on the d-pad. Now start the Showtime Road Rule event by pressing Lb+Rb / L1+R1. Keep pressing the A/X button to keep your momentum going and try to hit as many cars as possible. Most importantly you want to hit every bus you can find. This will give you an additional multiplier and makes this challenge a lot easier.