This trophy will take you over 4 hours total to complete. You DO NOT have to complete it in one sitting. If you want to save your progress partway through, simply hold down the "Home" button and select "Close Application". The game will automatically have your progress saved at whatever track you were on. HOWEVER, DO NOT select "Abort Endurance" in the game menu. Doing so will erase ALL progress and you will have to start over.
As for car recommendation i used Macchina because of it's high handling and well-rounded stats.