Simplify the following text for a Grade 5 native English-speaking person.
Original: The GP2 Series , GP2 for short , is a form of open wheel motor racing introduced in 2005 following the discontinuation of the long-term Formula One feeder series , Formula 3000 .
Simplified: The GP2 Series , GP2 for short , is a form of open wheel motor racing . GP2 was started in 2005 after the Formula 3000 was stopped .