Simplify the following text for a Grade 9 native English-speaking person.
Original: Constructors had complained about the poor quality of the facilities at Imola so , after much talk of dropping the San Marino Grand Prix from the Formula One championship , especially since there is another grand prix held in Italy , on 29 August 2006 , the race was excluded from the calendar released for the 2007 season , and has not featured since .
Simplified: Teams had complained about the poor quality of the facilities ( buildings and work areas ) at Imola . San Marino Grand Prix was dropped from the Formula One championship after .